Materiały źródłowe

• #1 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms that account for less than 2% of all soft tissue masses. […] The pathogenesis of SFT is often associated with the presence of fusions of the NAB2-STAT6 gene on the 12q13 chromosome. […] A key factor in the diagnosis is the prevalent nuclear location of STAT6 expression. […] SFTs remain a diagnostic challenge due to the lack of characteristic clinical features. […] Preoperative diagnosis by imaging of both pleural and extrapleural SFTs is challenging because findings are unspecific. […] The diagnostic modalities of choice are computed tomography (CT) scanning and magnetic resonance imaging (MRI). […] Interestingly, FNA (fine needle aspiration), together with nuclear STAT6 immunoreactivity, has been reported to be an additional tool in the diagnosis of SFTs.

• #2 Solitary fibrous tumor | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/solitary-fibrous-tumour?lang=us

  Solitary fibrous tumors are a rare neoplasm of mesenchymal origin that comprise less than 2% of all soft tissue tumors ranging from indolent tumors to more aggressive masses. […] The clinical presentation of solitary fibrous tumors is usually due to local mass effect and therefore will depend on the location and size of the tumor. […] Immunohistochemical analysis can play an important role in the diagnosis and management. Solitary fibrous tumors are usually positive for the following markers: STAT6 nuclear staining as a surrogate marker of NAB2-STAT6 gene fusion (most sensitive and specific), CD34, CD99, BCL-2, vimentin, cytokeratin, S-100, and p53 proteins have shown increased expression in aggressive solitary fibrous tumors. […] Solitary fibrous tumors, regardless of location, are characterized by the genomic inversion of 12q13 locus resulting in the fusion of NAB2 and STAT6 genes.

• #3 Solitary Fibrous Tumors – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK585038/

  Solitary fibrous tumors (SFTs) represent a rare type of mesenchymal neoplasm that can arise in various locations throughout the body, although most commonly occur in the thoracic cavity. […] Diagnosis often requires a multidisciplinary approach involving clinical, histological, immunohistochemical, and molecular assessments to differentiate SFTs from other soft tissue tumors. […] The emergence of NAB2-STAT6 gene fusion as a sensitive molecular marker and its surrogate STAT6 immunostaining enhances diagnostic accuracy. However, its specificity in distinguishing SFT from other soft tissue tumors warrants further investigation. […] The pathological diagnosis of SFT is confirmed based on histological characteristics and immunohistochemistry (IHC). […] IHC markers play a crucial role in diagnosing SFTs. CD34 and STAT6 strongly support the diagnosis of SFT, with CD99 and Bcl-2 also commonly used.

• #4 Pathology Outlines – Solitary fibrous tumor

  https://www.pathologyoutlines.com/topic/softtissuesft.html

  Fibroblastic tumor characterized by haphazardly arranged spindled to ovoid cells, prominent staghorn vasculature and NAB2-STAT6 gene rearrangement. […] Imaging features are nonspecific and diagnosis is dependent on histologic findings.

• #5 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms that account for less than 2% of all soft tissue masses. […] The pathogenesis of SFT is often associated with the presence of fusions of the NAB2-STAT6 gene on the 12q13 chromosome. […] A key factor in the diagnosis is the prevalent nuclear location of STAT6 expression. […] SFTs remain a diagnostic challenge due to the lack of characteristic clinical features. […] Preoperative diagnosis by imaging of both pleural and extrapleural SFTs is challenging because findings are unspecific. […] The diagnostic modalities of choice are computed tomography (CT) scanning and magnetic resonance imaging (MRI). […] Interestingly, FNA (fine needle aspiration), together with nuclear STAT6 immunoreactivity, has been reported to be an additional tool in the diagnosis of SFTs.

• #6 Solitary fibrous tumor – Overview – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/solitary-fibrous-tumors/cdc-20395823

  Solitary fibrous tumors are growths of cells that can form in almost any part of the body. […] Solitary fibrous tumors are rare. They mainly affect older adults. […] Treatment for solitary fibrous tumor often involves surgery to remove the tumor. […] Tests and procedures used to diagnose solitary fibrous tumors include imaging tests and a procedure to remove some tissue for testing, called a biopsy. […] Imaging tests make pictures of the body. They can show where a solitary fibrous tumor is, how large it is and if it has spread to other areas of the body. […] A biopsy is a procedure to remove a sample of tissue for testing in a lab. […] The sample is tested in a lab to see if it is cancer. Testing is done by doctors who specialize in analyzing blood and body tissue, called pathologists. […] Your healthcare team uses this information to make a treatment plan.

• #7 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms that account for less than 2% of all soft tissue masses. […] The pathogenesis of SFT is often associated with the presence of fusions of the NAB2-STAT6 gene on the 12q13 chromosome. […] A key factor in the diagnosis is the prevalent nuclear location of STAT6 expression. […] SFTs remain a diagnostic challenge due to the lack of characteristic clinical features. […] Preoperative diagnosis by imaging of both pleural and extrapleural SFTs is challenging because findings are unspecific. […] The diagnostic modalities of choice are computed tomography (CT) scanning and magnetic resonance imaging (MRI). […] Interestingly, FNA (fine needle aspiration), together with nuclear STAT6 immunoreactivity, has been reported to be an additional tool in the diagnosis of SFTs.

• #8

  https://journals.lww.com/lungindia/fulltext/2012/29020/giant_solitary_fibrous_tumor_pleura__clinical.18.aspx

  Solitary fibrous tumors in the lung are rare neoplasms with distinct clinicopathological and immunohistochemical features. […] This case depicts the vulnerability of this lesion to a clinical bungle. The report highlights the significance of clinical suspicion of this rare neoplasm and reveals the diagnostic associations and procedures to avoid empirical therapy and delay in curative surgical treatment. […] The patient was initially placed on antitubercular treatment. It was only when attempted pleural taps failed and help from the ultrasonologist was sought that information of the presence of a solid neoplasm mimicking pleural effusion on chest X-ray could be revealed. […] A USG-guided fine needle aspiration and trucut biopsy thereafter revealed a cellular but benign spindle cell neoplasm.

• #9 Extra-pleural solitary fibrous tumors: a review | Egyptian Journal of Radiology and Nuclear Medicine | Full Text

  https://ejrnm.springeropen.com/articles/10.1186/s43055-019-0040-9

  According to the WHO classification SFTs are classified as having intermediate malignant potential with low risk of metastasis. […] The malignant potential of extrapleural SFTs is similar to pleural tumors, with malignant features detected at pathologic examination in up to 20%. […] Surgical excision is the treatment of choice for all SFTs. […] The treatment of unresectable SFTs is challenging. […] A high index of suspicion of SFT should be raised in a deep heterogeneously enhancing soft tissue extrapleural mass in which MRI suggests fibrous content. […] A frequent and unifying feature of SFT at MR imaging is the presence of low signal-intensity foci on T1- and T2-weighted images, corresponding to the collagen content. […] When a central focus of heterogeneity and variable contrast enhancement is identified in CT or MR images, malignant degeneration should be considered.

• #10 Intracranial Solitary Fibrous Tumour | Journal of the Belgian Society of Radiology

  https://jbsr.be/articles/10.5334/jbr-btr.1213

  Solitary fibrous tumours are rare mesenchymal spindle-cell tumours that occur most often in the visceral pleura or liver. If they occur intracranially, they are extra-axially located and develop from the meninges. […] Pre-operative definitive diagnosis is difficult due to the atypical imaging characteristics, but the differential diagnosis can be limited by imaging. […] The definitive diagnosis in this case was made by histologic examination, which showed a solitary fibrous tumour. […] The imaging characteristics of ISFTs have been described by Clarenon et al., based on a restrospective cohort of nine patients. […] The combination of these two components gives rise to the so-called yin yang sign, which is associated with ISFTs. […] There is currently no guideline regarding the optimal therapeutic approach for SFTs. Total excision of the mass is clearly superior to subtotal resection, with a 16-fold increase in recurrence ratio with subtotal resection (without adjuvant therapy), compared to total resection.

• #11 Intracranial Solitary Fibrous Tumors: Imaging Findings in 6 Consecutive Patients | American Journal of Neuroradiology

  http://www.ajnr.org/content/28/8/1466

  BACKGROUND AND PURPOSE: Intracranial solitary fibrous tumors (ISFTs) are rare mesenchymal neoplasms originating in the meninges. The aim of this study was to describe the CT, MR imaging, and angiographic features of the solitary fibrous tumor and to identify imaging characteristics. […] The purpose of this study was to describe the MR imaging, CT imaging, and angiographic features of pathologically proven ISFT and to identify imaging characteristics. […] Although there are no pathognomonic imaging findings, some imaging features, such as the black-and-white mixed pattern on T2-weighted images and marked heterogeneous enhancement, might be helpful in the diagnosis of intracranial solitary fibrous tumor. […] In our study, 5 (83%) of 6 SFTs had 2 different portions with low and high signal intensities on T2-weighted imaging.

• #12 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms that account for less than 2% of all soft tissue masses. […] The pathogenesis of SFT is often associated with the presence of fusions of the NAB2-STAT6 gene on the 12q13 chromosome. […] A key factor in the diagnosis is the prevalent nuclear location of STAT6 expression. […] SFTs remain a diagnostic challenge due to the lack of characteristic clinical features. […] Preoperative diagnosis by imaging of both pleural and extrapleural SFTs is challenging because findings are unspecific. […] The diagnostic modalities of choice are computed tomography (CT) scanning and magnetic resonance imaging (MRI). […] Interestingly, FNA (fine needle aspiration), together with nuclear STAT6 immunoreactivity, has been reported to be an additional tool in the diagnosis of SFTs.

• #13 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  However, a core needle biopsy or an open incisional biopsy and an immunohistochemical analysis are needed to confirm the diagnosis. […] The metastatic rate of SFTs is up to 35–45%. […] Furthermore, tumors classified primarily as benign may show malignant behavior many years after initial diagnosis. […] For this reason, patients require long-term observation, especially those with tumors greater than 10 cm. […] The presence of cells positive for desmin distinguishes tumors from desmoid. […] At the same time, actin-positive staining and myxoid parts represent nodular fasciitis. […] When SFTs differentiate from immunohistochemically similar tumors, STAT6 positive staining and the specific pattern of the vessels are crucial. […] The cornerstone of SFT pathogenesis is linked to the presence of NAB2-STAT6 gene fusion from the 12q13 chromosome.

• #14 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms that account for less than 2% of all soft tissue masses. […] The pathogenesis of SFT is often associated with the presence of fusions of the NAB2-STAT6 gene on the 12q13 chromosome. […] A key factor in the diagnosis is the prevalent nuclear location of STAT6 expression. […] SFTs remain a diagnostic challenge due to the lack of characteristic clinical features. […] Preoperative diagnosis by imaging of both pleural and extrapleural SFTs is challenging because findings are unspecific. […] The diagnostic modalities of choice are computed tomography (CT) scanning and magnetic resonance imaging (MRI). […] Interestingly, FNA (fine needle aspiration), together with nuclear STAT6 immunoreactivity, has been reported to be an additional tool in the diagnosis of SFTs.

• #15 Solitary Fibrous Tumors – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK585038/

  Solitary fibrous tumors (SFTs) represent a rare type of mesenchymal neoplasm that can arise in various locations throughout the body, although most commonly occur in the thoracic cavity. […] Diagnosis often requires a multidisciplinary approach involving clinical, histological, immunohistochemical, and molecular assessments to differentiate SFTs from other soft tissue tumors. […] The emergence of NAB2-STAT6 gene fusion as a sensitive molecular marker and its surrogate STAT6 immunostaining enhances diagnostic accuracy. However, its specificity in distinguishing SFT from other soft tissue tumors warrants further investigation. […] The pathological diagnosis of SFT is confirmed based on histological characteristics and immunohistochemistry (IHC). […] IHC markers play a crucial role in diagnosing SFTs. CD34 and STAT6 strongly support the diagnosis of SFT, with CD99 and Bcl-2 also commonly used.

• #16 Solitary Fibrous Tumors – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK585038/

  However, their utility is limited due to their expression in other neoplasms that mimic SFT histologically. […] The excised tissue sample is sent to a pathology laboratory for histopathological examination by a pathologist. This examination involves analyzing the tissue under a microscope to evaluate its cellular composition, architecture, and other features characteristic of SFTs. Histopathological examination confirms the diagnosis of SFT based on characteristic morphological features such as spindle-shaped cells, patternless growth, and branching „staghorn” blood vessels. […] Molecular testing may also detect the characteristic NAB2-STAT6 gene fusion, providing further diagnostic confirmation.

• #17 Solitary fibrous tumor – Overview – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/solitary-fibrous-tumors/cdc-20395823

  Solitary fibrous tumors are growths of cells that can form in almost any part of the body. […] Solitary fibrous tumors are rare. They mainly affect older adults. […] Treatment for solitary fibrous tumor often involves surgery to remove the tumor. […] Tests and procedures used to diagnose solitary fibrous tumors include imaging tests and a procedure to remove some tissue for testing, called a biopsy. […] Imaging tests make pictures of the body. They can show where a solitary fibrous tumor is, how large it is and if it has spread to other areas of the body. […] A biopsy is a procedure to remove a sample of tissue for testing in a lab. […] The sample is tested in a lab to see if it is cancer. Testing is done by doctors who specialize in analyzing blood and body tissue, called pathologists. […] Your healthcare team uses this information to make a treatment plan.

• #18 Diagnostic challenges and treatment options in patients with solitary fibrous tumor: A single-center observational study

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9583656/

  Solitary fibrous tumor (SFT) is an extremely rare disease with a high misdiagnosis rate and a potentially malignant biologic nature. […] In three patients, the preoperative diagnosis did not correlate with the definitive histology of SFT. […] The diagnosis of SFT is usually made upon a combination of imaging techniques, pretreatment biopsy, and histopathological evaluation. […] Our data indicated that the preoperative misdiagnosis rate was high and corroborated that of previously published studies by Chu et al. and Kim et al. […] In 17% of our patients, the preoperative diagnosis did not match the postoperative histology. […] The need for obtaining negative resection margins stems from the fact that SFTs have uncertain biological behavior and a high rate of local recurrences. […] The mainstay of SFT treatment remains radical surgery, where obtaining negative resection margins is the most important factor preventing the disease recurrence. […] While radiotherapy alone can significantly improve the overall survival of patients, we believe that more therapies, mainly targeted therapy and immunotherapy, should become a part of the sophisticated therapeutic scheme in SFT.

• #19 Solitary Fibrous Tumors – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK585038/

  Solitary fibrous tumors (SFTs) represent a rare type of mesenchymal neoplasm that can arise in various locations throughout the body, although most commonly occur in the thoracic cavity. […] Diagnosis often requires a multidisciplinary approach involving clinical, histological, immunohistochemical, and molecular assessments to differentiate SFTs from other soft tissue tumors. […] The emergence of NAB2-STAT6 gene fusion as a sensitive molecular marker and its surrogate STAT6 immunostaining enhances diagnostic accuracy. However, its specificity in distinguishing SFT from other soft tissue tumors warrants further investigation. […] The pathological diagnosis of SFT is confirmed based on histological characteristics and immunohistochemistry (IHC). […] IHC markers play a crucial role in diagnosing SFTs. CD34 and STAT6 strongly support the diagnosis of SFT, with CD99 and Bcl-2 also commonly used.

• #20 Solitary fibrous tumor | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/solitary-fibrous-tumour?lang=us

  Solitary fibrous tumors are a rare neoplasm of mesenchymal origin that comprise less than 2% of all soft tissue tumors ranging from indolent tumors to more aggressive masses. […] The clinical presentation of solitary fibrous tumors is usually due to local mass effect and therefore will depend on the location and size of the tumor. […] Immunohistochemical analysis can play an important role in the diagnosis and management. Solitary fibrous tumors are usually positive for the following markers: STAT6 nuclear staining as a surrogate marker of NAB2-STAT6 gene fusion (most sensitive and specific), CD34, CD99, BCL-2, vimentin, cytokeratin, S-100, and p53 proteins have shown increased expression in aggressive solitary fibrous tumors. […] Solitary fibrous tumors, regardless of location, are characterized by the genomic inversion of 12q13 locus resulting in the fusion of NAB2 and STAT6 genes.

• #21 Role of Immunohistochemistry in the Diagnosis of Solitary Fibrous Tumor, a Review

  https://ijp.iranpath.org/article_19723.html

  Solitary fibrous tumor (SFT) is a mesenchymal tumor which is most commonly seen in the pleura; however it can be seen in other organs such as the meninge, gastrointestinal tract, soft tissue, bone, and skin. […] Immunohistochemistry plays a pivotal role for the histopathologic diagnosis of this tumor. […] Currently, new markers have been introduced which has been very useful for definite diagnosis of SFT along with other markers in each specific location which are negative in SFT. […] Immunohistochemistry is very useful for the diagnosis of solitary fibrous tumor and for its differentiation with other spindle cell mesenchymal tumor in different locations. […] The most important and valuable positive markers in SFT are CD34, CD99, Bcl-2 and STAT-6. […] There are consistently negative markers in this tumor as well, used according to the tumor location, such as EMA and S100.

• #22 Nuclear expression of STAT6 distinguishes solitary fibrous tumor from histologic mimics | Modern Pathology

  https://www.nature.com/articles/modpathol2013164

  We investigated STAT6 expression by immunohistochemistry in SFTs and other soft tissue tumors arising outside the central nervous system to validate the diagnostic utility of this novel marker. […] Fifty-nine of 60 SFT cases (98%) showed nuclear expression of STAT6, which was usually diffuse and intense. […] In conclusion, STAT6 is a highly sensitive and almost perfectly specific immunohistochemical marker for SFT and can be helpful to distinguish this tumor type from histologic mimics. […] Although in most cases the diagnosis of SFT is relatively straightforward, some tumors may mimic other benign mesenchymal tumors or sarcomas, and a subset of SFTs lack expression of CD34. […] In this study, we investigated STAT6 protein expression by immunohistochemistry in SFT and histologic mimics to validate the utility of STAT6 as a diagnostic marker.

• #23 Nuclear expression of STAT6 distinguishes solitary fibrous tumor from histologic mimics | Modern Pathology

  https://www.nature.com/articles/modpathol2013164

  Solitary fibrous tumor (SFT) is composed of spindled to ovoid cells in a patternless architecture with prominent stromal collagen and hemangiopericytoma-like vessels. […] SFT can sometimes be difficult to distinguish from other benign mesenchymal tumors and sarcomas. […] The most characteristic (albeit nonspecific) immunohistochemical finding in SFT is CD34 expression. […] A NAB2STAT6 gene fusion, resulting in a chimeric protein in which a repressor domain of NGFI-A binding protein 2 (EGR1 binding protein 2) (NAB2) is replaced with a carboxy-terminal transactivation domain from signal transducer and activator of transcription 6, interleukin-4 induced (STAT6), was recently identified as a consistent finding in SFT. […] Nuclear expression of the carboxy terminal part of STAT6 is a consistent finding in SFT of the meninges (so-called meningeal hemangiopericytoma).

• #24 Solitary fibrous tumour – Libre Pathology

  https://librepathology.org/wiki/Solitary_fibrous_tumour

  Solitary fibrous tumour. HE stain. LM spindle cells in a patternless pattern, hemangiopericytoma-like areas (staghorn vessels), keloid-like collagen bundles, +/-well-circumscribed (common) Subtypes benign (common), malignant (uncommon) IHC CD34 ~90% +ve, CD99 ~70% +ve, BCL2 ~50% +ve Site soft tissue – fibroblastic/myofibroblastic tumours, pleura […] May be benign or malignant; more commonly benign. […] Criteria for malignancy: Necrosis. Mitoses 4/10 HPF — definition suffers from HPFitis. Increased cellularity. Marked nuclear atypia. Infiltrative margin. […] STAT 6 positivity is very helpful in separating this tumor from its mimics.

• #25 Solitary fibrous tumour – Libre Pathology

  https://librepathology.org/wiki/Solitary_fibrous_tumour

  Solitary fibrous tumour. HE stain. LM spindle cells in a patternless pattern, hemangiopericytoma-like areas (staghorn vessels), keloid-like collagen bundles, +/-well-circumscribed (common) Subtypes benign (common), malignant (uncommon) IHC CD34 ~90% +ve, CD99 ~70% +ve, BCL2 ~50% +ve Site soft tissue – fibroblastic/myofibroblastic tumours, pleura […] May be benign or malignant; more commonly benign. […] Criteria for malignancy: Necrosis. Mitoses 4/10 HPF — definition suffers from HPFitis. Increased cellularity. Marked nuclear atypia. Infiltrative margin. […] STAT 6 positivity is very helpful in separating this tumor from its mimics.

• #26 Solitary fibrous tumour – Libre Pathology

  https://librepathology.org/wiki/Solitary_fibrous_tumour

  Solitary fibrous tumour. HE stain. LM spindle cells in a patternless pattern, hemangiopericytoma-like areas (staghorn vessels), keloid-like collagen bundles, +/-well-circumscribed (common) Subtypes benign (common), malignant (uncommon) IHC CD34 ~90% +ve, CD99 ~70% +ve, BCL2 ~50% +ve Site soft tissue – fibroblastic/myofibroblastic tumours, pleura […] May be benign or malignant; more commonly benign. […] Criteria for malignancy: Necrosis. Mitoses 4/10 HPF — definition suffers from HPFitis. Increased cellularity. Marked nuclear atypia. Infiltrative margin. […] STAT 6 positivity is very helpful in separating this tumor from its mimics.

• #27 Solitary fibrous tumor | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/solitary-fibrous-tumour?lang=us

  Solitary fibrous tumors are a rare neoplasm of mesenchymal origin that comprise less than 2% of all soft tissue tumors ranging from indolent tumors to more aggressive masses. […] The clinical presentation of solitary fibrous tumors is usually due to local mass effect and therefore will depend on the location and size of the tumor. […] Immunohistochemical analysis can play an important role in the diagnosis and management. Solitary fibrous tumors are usually positive for the following markers: STAT6 nuclear staining as a surrogate marker of NAB2-STAT6 gene fusion (most sensitive and specific), CD34, CD99, BCL-2, vimentin, cytokeratin, S-100, and p53 proteins have shown increased expression in aggressive solitary fibrous tumors. […] Solitary fibrous tumors, regardless of location, are characterized by the genomic inversion of 12q13 locus resulting in the fusion of NAB2 and STAT6 genes.

• #28 Role of Immunohistochemistry in the Diagnosis of Solitary Fibrous Tumor, a Review

  https://ijp.iranpath.org/article_19723.html

  A combination of positive CD34 and Bcl-2 is highly characteristics of SFT. […] The only exception to this is malignant and dedifferentiated cases of SFT in which the percentage of CD34 positivity is lower, but still significant (83%). […] In such cases, cytokeratin (CK) will be positive and CK positivity accompanied with negative CD34 is an indication for this tumor to be dedifferentiated or malignant and to behave aggressively, in which the tumor is still recognizable as SFT but has cytologically malignant features. […] By using this marker, SFT can be accurately differentiated from other histologic mimics such as meningeal hemangiopericytoma. […] The best positive markers in mesothelioma that are mostly negative in SFT are cytokeratin (CK), calretinin, WT-1, CK5/6. […] Immunohistochemistry plays a pivotal role for this differential diagnosis, because in all of the previous studies, EMA and S100 have been consistently negative in SFT, as opposed to meningioma which is consistently reactive with S100 and EMA.

• #29 Role of Immunohistochemistry in the Diagnosis of Solitary Fibrous Tumor, a Review

  https://ijp.iranpath.org/article_19723.html

  A combination of positive CD34 and Bcl-2 is highly characteristics of SFT. […] The only exception to this is malignant and dedifferentiated cases of SFT in which the percentage of CD34 positivity is lower, but still significant (83%). […] In such cases, cytokeratin (CK) will be positive and CK positivity accompanied with negative CD34 is an indication for this tumor to be dedifferentiated or malignant and to behave aggressively, in which the tumor is still recognizable as SFT but has cytologically malignant features. […] By using this marker, SFT can be accurately differentiated from other histologic mimics such as meningeal hemangiopericytoma. […] The best positive markers in mesothelioma that are mostly negative in SFT are cytokeratin (CK), calretinin, WT-1, CK5/6. […] Immunohistochemistry plays a pivotal role for this differential diagnosis, because in all of the previous studies, EMA and S100 have been consistently negative in SFT, as opposed to meningioma which is consistently reactive with S100 and EMA.

• #30 Role of Immunohistochemistry in the Diagnosis of Solitary Fibrous Tumor, a Review

  https://ijp.iranpath.org/article_19723.html

  A combination of positive CD34 and Bcl-2 is highly characteristics of SFT. […] The only exception to this is malignant and dedifferentiated cases of SFT in which the percentage of CD34 positivity is lower, but still significant (83%). […] In such cases, cytokeratin (CK) will be positive and CK positivity accompanied with negative CD34 is an indication for this tumor to be dedifferentiated or malignant and to behave aggressively, in which the tumor is still recognizable as SFT but has cytologically malignant features. […] By using this marker, SFT can be accurately differentiated from other histologic mimics such as meningeal hemangiopericytoma. […] The best positive markers in mesothelioma that are mostly negative in SFT are cytokeratin (CK), calretinin, WT-1, CK5/6. […] Immunohistochemistry plays a pivotal role for this differential diagnosis, because in all of the previous studies, EMA and S100 have been consistently negative in SFT, as opposed to meningioma which is consistently reactive with S100 and EMA.

• #31 Role of Immunohistochemistry in the Diagnosis of Solitary Fibrous Tumor, a Review

  https://ijp.iranpath.org/article_19723.html

  Solitary fibrous tumor (SFT) is a mesenchymal tumor which is most commonly seen in the pleura; however it can be seen in other organs such as the meninge, gastrointestinal tract, soft tissue, bone, and skin. […] Immunohistochemistry plays a pivotal role for the histopathologic diagnosis of this tumor. […] Currently, new markers have been introduced which has been very useful for definite diagnosis of SFT along with other markers in each specific location which are negative in SFT. […] Immunohistochemistry is very useful for the diagnosis of solitary fibrous tumor and for its differentiation with other spindle cell mesenchymal tumor in different locations. […] The most important and valuable positive markers in SFT are CD34, CD99, Bcl-2 and STAT-6. […] There are consistently negative markers in this tumor as well, used according to the tumor location, such as EMA and S100.

• #32 Role of Immunohistochemistry in the Diagnosis of Solitary Fibrous Tumor, a Review

  https://ijp.iranpath.org/article_19723.html

  A combination of positive CD34 and Bcl-2 is highly characteristics of SFT. […] The only exception to this is malignant and dedifferentiated cases of SFT in which the percentage of CD34 positivity is lower, but still significant (83%). […] In such cases, cytokeratin (CK) will be positive and CK positivity accompanied with negative CD34 is an indication for this tumor to be dedifferentiated or malignant and to behave aggressively, in which the tumor is still recognizable as SFT but has cytologically malignant features. […] By using this marker, SFT can be accurately differentiated from other histologic mimics such as meningeal hemangiopericytoma. […] The best positive markers in mesothelioma that are mostly negative in SFT are cytokeratin (CK), calretinin, WT-1, CK5/6. […] Immunohistochemistry plays a pivotal role for this differential diagnosis, because in all of the previous studies, EMA and S100 have been consistently negative in SFT, as opposed to meningioma which is consistently reactive with S100 and EMA.

• #33 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms that account for less than 2% of all soft tissue masses. […] The pathogenesis of SFT is often associated with the presence of fusions of the NAB2-STAT6 gene on the 12q13 chromosome. […] A key factor in the diagnosis is the prevalent nuclear location of STAT6 expression. […] SFTs remain a diagnostic challenge due to the lack of characteristic clinical features. […] Preoperative diagnosis by imaging of both pleural and extrapleural SFTs is challenging because findings are unspecific. […] The diagnostic modalities of choice are computed tomography (CT) scanning and magnetic resonance imaging (MRI). […] Interestingly, FNA (fine needle aspiration), together with nuclear STAT6 immunoreactivity, has been reported to be an additional tool in the diagnosis of SFTs.

• #34 The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior | Diagnostic Pathology | Full Text

  https://diagnosticpathology.biomedcentral.com/articles/10.1186/s13000-021-01095-2

  Solitary Fibrous Tumor (SFT) is a distinct soft tissue neoplasm associated with NAB2-STAT6 gene fusion. It can involve a number of anatomic sites and exhibits a wide spectrum of histological features. […] The management and prognosis of SFT differs from its malignant mimics and correct diagnosis is therefore important. […] Although SFT expresses a distinct immunohistochemical (IHC) profile, the classic histomorphological and IHC profile is not seen in all cases and diagnosis can be challenging. […] NAB2-STAT6 gene fusion has recently emerged as a sensitive and specific molecular marker and its IHC surrogate marker signal transducer and activator of transcription 6 (STAT6) has also shown significant sensitivity and specificity. […] This review will focus on describing the diversity of histological features of SFT, differential diagnoses and discussing the features helpful in distinguishing SFT from its histological mimics.

• #35

  https://link.springer.com/article/10.1007/s10555-024-10204-8

  Solitary fibrous tumor (SFT) is a rare fibroblastic mesenchymal neoplasm. […] Diagnostic methods play a crucial role in SFT clinical practice and basic research, including RT-PCR, next-generation sequencing (NGS), FISH, immunohistochemistry (IHC), and Western blot analysis, each with distinct capabilities and limitations. […] Diagnostic methods are crucial in SFT research and clinics, including RT-PCR, NGS, FISH, IHC, and Western blot analysis. Each of these offers distinct capabilities and challenges. RT-PCR is adept at detecting known fusions, while NGS provides comprehensive genomic insights. FISH reveals NAB2-STAT6 gene fusion, while IHC and Western blot demonstrate significant value in NAB2-STAT6 protein assessment. […] In this review, we summarize the latest developments in the clinical characteristics and molecular mechanisms of SFT, aiming to provide an update on the diagnostic methods and potential breakthroughs in treatments.

• #36 Solitary fibrous tumor – Davanzo – Translational Gastroenterology and Hepatology

  https://tgh.amegroups.org/article/view/4708/html

  Molecular genetic analysis has proven vital in further differentiating soft tissue masses for diagnosis. SFT has recently been associated with a NAB2-STAT6 gene fusion product that has proven to be highly specific and sensitive for SFT. […] Strong nuclear STAT6 IHC staining has been used to reliably differentiate SFT from other soft tissue tumors, tumors of the head and neck, gynecologic tract and prostate. […] Recently, multiple groups discovered a gene fusion product between NAB2 and STAT6, which is a highly sensitive and specific marker for SFT and is considered the molecular hallmark of SFT. […] The 2013 World Health Organization classification of soft tissue sarcomas helped further differentiate many sarcomas with SFT being classified as a fibroblastic/myofibroblastic tumor. […] Given the rarity of SFT and mostly retrospective data from small cases series, there is still much progress to be made. […] While surgical resection is the mainstay of treatment and provides favorable outcomes for resectable disease, radiation and chemotherapy may have potential roles in the treatment algorithm.

• #37

  https://link.springer.com/article/10.1007/s10555-024-10204-8

  RT-PCR is used to amplify and detect mRNA molecules. SFT is known to be associated with specific NAB2-STAT6 fusion genes. Hence, RT-PCR can be employed as a molecular diagnostic approach to see the fusion genes in SFT. […] NGS allows for comprehensive genomic profiling of SFT, enabling the identification of specific genetic alterations, mutations, and chromosomal rearrangements associated with it. The characteristic translocation involving the NAB2 and STAT6 genes is a hallmark of SFT. NGS can detect the NAB2-STAT6 fusion gene, providing a molecular signature for diagnosing SFT. […] FISH has proven applicable in the molecular diagnosis of SFT. A study revealed the presence of the NAB2-STAT6 gene fusion in 64% of cases through the split-apart FISH probes. […] SFT typically manifests a profile characterized by the simultaneous presence of CD34, CD99, and BCL-2, historically considered diagnostic factors owing to their notable expression in nearly 90% of cases. […] The expression of NAB2-STAT6 in SFT can also be confirmed by Western blotting analysis.

• #38 Solitary fibrous tumors: loss of chimeric protein expression and genomic instability mark dedifferentiation | Modern Pathology

  https://www.nature.com/articles/modpathol201570

  The discovery of the NAB2/STAT6 fusion made it possible to diagnose solitary fibrous tumor molecularly using reverse-transcription polymerase chain reaction; moreover, the overexpression and phosphorylation-independent nuclear translocation of the STAT6 C-terminus can be readily identified by means of STAT6 immunohistochemistry, a sensitive, specific and more widely available means of accurate diagnosis. […] The results confirm that reverse-transcription polymerase chain reaction is the diagnostic gold standard albeit with some limitations due to the broad splicing landscape and the frequent occurrence of noncanonical NAB2/STAT6 fusions. […] A reliable and widely applicable alternative means of diagnosing solitary fibrous tumors is STAT6 immunostaining, which is characterized by strong and diffuse nuclear immunopositivity.

• #39

  https://link.springer.com/article/10.1007/s10555-024-10204-8

  RT-PCR is used to amplify and detect mRNA molecules. SFT is known to be associated with specific NAB2-STAT6 fusion genes. Hence, RT-PCR can be employed as a molecular diagnostic approach to see the fusion genes in SFT. […] NGS allows for comprehensive genomic profiling of SFT, enabling the identification of specific genetic alterations, mutations, and chromosomal rearrangements associated with it. The characteristic translocation involving the NAB2 and STAT6 genes is a hallmark of SFT. NGS can detect the NAB2-STAT6 fusion gene, providing a molecular signature for diagnosing SFT. […] FISH has proven applicable in the molecular diagnosis of SFT. A study revealed the presence of the NAB2-STAT6 gene fusion in 64% of cases through the split-apart FISH probes. […] SFT typically manifests a profile characterized by the simultaneous presence of CD34, CD99, and BCL-2, historically considered diagnostic factors owing to their notable expression in nearly 90% of cases. […] The expression of NAB2-STAT6 in SFT can also be confirmed by Western blotting analysis.

• #40

  https://link.springer.com/article/10.1007/s10555-024-10204-8

  RT-PCR is used to amplify and detect mRNA molecules. SFT is known to be associated with specific NAB2-STAT6 fusion genes. Hence, RT-PCR can be employed as a molecular diagnostic approach to see the fusion genes in SFT. […] NGS allows for comprehensive genomic profiling of SFT, enabling the identification of specific genetic alterations, mutations, and chromosomal rearrangements associated with it. The characteristic translocation involving the NAB2 and STAT6 genes is a hallmark of SFT. NGS can detect the NAB2-STAT6 fusion gene, providing a molecular signature for diagnosing SFT. […] FISH has proven applicable in the molecular diagnosis of SFT. A study revealed the presence of the NAB2-STAT6 gene fusion in 64% of cases through the split-apart FISH probes. […] SFT typically manifests a profile characterized by the simultaneous presence of CD34, CD99, and BCL-2, historically considered diagnostic factors owing to their notable expression in nearly 90% of cases. […] The expression of NAB2-STAT6 in SFT can also be confirmed by Western blotting analysis.

• #41 Differential diagnosis of solitary fibrous tumors: A study of 454 soft tissue tumors indicating the diagnostic value of nuclear STAT6 relocation and ALDH1 expression combined with in situ proximity ligation assay

  https://www.spandidos-publications.com/10.3892/ijo.2015.2975

  We observed nuclear STAT6 expression in all 80 SFT cases and additional cytoplasmic STAT6 expression in 8 tumors which is in line with previous findings. […] In summary, nuclear expression of STAT6 is the most specific diagnostic immunohistochemical marker of SFT. […] Overall, the Duolink proximity ligation assay is a useful molecular technique for the detection of NAB2-STAT6 fusion proteins, with the vast majority of SFT cases (71/78 cases; 91%) shown to be positive for the proximate co-localization of STAT6 and NAB2 antigens. […] In summary, we propose the following algorithm to establish a reliable diagnosis of SFTs: i) standard HE morphology with variable cellularity and high vascularity including the so-called staghorn thick wall vessels, combined with ii) immunohistochemistry for the detection of nuclear STAT6 (validated as the most specific and highly sensitive marker for SFTs), ALDH1 and CD34 positivity.

• #42 Solitary fibrous tumors: loss of chimeric protein expression and genomic instability mark dedifferentiation | Modern Pathology

  https://www.nature.com/articles/modpathol201570

  Taken together, these findings suggest that reverse-transcription polymerase chain reaction is the diagnostic gold standard for solitary fibrous tumors as it can detect NAB2/STAT6 fusions throughout the spectrum, including dedifferentiated variants that have lost their immunohistochemical signature. […] Cumulatively, the main features of dedifferentiated solitary fibrous tumors are the complete or partial loss of NAB2/STAT6 chimeric protein expression (despite the retention of chimeric RNA expression), and the acquisition of genome instability.

• #43 Solitary fibrous tumors: loss of chimeric protein expression and genomic instability mark dedifferentiation | Modern Pathology

  https://www.nature.com/articles/modpathol201570

  The discovery of the NAB2/STAT6 fusion made it possible to diagnose solitary fibrous tumor molecularly using reverse-transcription polymerase chain reaction; moreover, the overexpression and phosphorylation-independent nuclear translocation of the STAT6 C-terminus can be readily identified by means of STAT6 immunohistochemistry, a sensitive, specific and more widely available means of accurate diagnosis. […] The results confirm that reverse-transcription polymerase chain reaction is the diagnostic gold standard albeit with some limitations due to the broad splicing landscape and the frequent occurrence of noncanonical NAB2/STAT6 fusions. […] A reliable and widely applicable alternative means of diagnosing solitary fibrous tumors is STAT6 immunostaining, which is characterized by strong and diffuse nuclear immunopositivity.

• #44 Differential diagnosis of solitary fibrous tumors: A study of 454 soft tissue tumors indicating the diagnostic value of nuclear STAT6 relocation and ALDH1 expression combined with in situ proximity ligation assay

  https://www.spandidos-publications.com/10.3892/ijo.2015.2975

  We observed nuclear STAT6 expression in all 80 SFT cases and additional cytoplasmic STAT6 expression in 8 tumors which is in line with previous findings. […] In summary, nuclear expression of STAT6 is the most specific diagnostic immunohistochemical marker of SFT. […] Overall, the Duolink proximity ligation assay is a useful molecular technique for the detection of NAB2-STAT6 fusion proteins, with the vast majority of SFT cases (71/78 cases; 91%) shown to be positive for the proximate co-localization of STAT6 and NAB2 antigens. […] In summary, we propose the following algorithm to establish a reliable diagnosis of SFTs: i) standard HE morphology with variable cellularity and high vascularity including the so-called staghorn thick wall vessels, combined with ii) immunohistochemistry for the detection of nuclear STAT6 (validated as the most specific and highly sensitive marker for SFTs), ALDH1 and CD34 positivity.

• #45 The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior | Diagnostic Pathology | Full Text

  https://diagnosticpathology.biomedcentral.com/articles/10.1186/s13000-021-01095-2

  Accurate diagnosis is essential for appropriate treatment and management of SFTs. NAB2-STAT6 gene fusion and its IHC expression are consistently observed in these tumors. Immunohistochemistry is the most sensitive and specific means of diagnosing SFT and is practical and economical as well. […] Molecular studies require expensive equipment and well-trained staff which reduces their practicality and feasibility in resource limited laboratories of developing countries. Molecular testing may be helpful where IHC results are ambiguous. Thorough knowledge about the morphological variations of SFTs and correlation with clinical, IHC and molecular features are helpful in avoiding misdiagnosis.

• #46 Nuclear expression of STAT6 distinguishes solitary fibrous tumor from histologic mimics | Modern Pathology

  https://www.nature.com/articles/modpathol2013164

  The discovery of a recurrent gene fusion by whole-exome and transcriptome sequencing is a novel method of detecting translocation-associated sarcomas. […] This adds to the expanding group of markers for soft tissue tumors identified through molecular genetic methods. […] Nuclear expression of STAT6 is found in nearly all cases of SFT and is very limited in other soft tissue neoplasms. STAT6 is therefore a highly sensitive and almost perfectly specific immunohistochemical marker for SFT, and can be helpful to distinguish this tumor type from histologic mimics.

• #47 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  However, a core needle biopsy or an open incisional biopsy and an immunohistochemical analysis are needed to confirm the diagnosis. […] The metastatic rate of SFTs is up to 35–45%. […] Furthermore, tumors classified primarily as benign may show malignant behavior many years after initial diagnosis. […] For this reason, patients require long-term observation, especially those with tumors greater than 10 cm. […] The presence of cells positive for desmin distinguishes tumors from desmoid. […] At the same time, actin-positive staining and myxoid parts represent nodular fasciitis. […] When SFTs differentiate from immunohistochemically similar tumors, STAT6 positive staining and the specific pattern of the vessels are crucial. […] The cornerstone of SFT pathogenesis is linked to the presence of NAB2-STAT6 gene fusion from the 12q13 chromosome.

• #48

  http://waocp.com/journal/index.php/apjcc/article/view/1301

  Solitary fibrous tumor (SFT) is an uncommon mesenchymal tumor, generally exhibiting indolent clinical behavior compared to its malignant counterpart. […] Malignant SFTs are furthermore extremely unusual in the mediastinal region, with a relatively aggressive course and inferior disease-specific survival. […] A CT- guided transthoracic core biopsy of the mediastinal mass was performed, which revealed a moderately cellular spindle cell tumor in a collagenous stroma with prominent dilated staghorn vasculature and no mitosis and tumor necrosis was seen. […] Final diagnosis of solitary fibrous tumor was reached at. […] On Immunohistochemistry (IHC), the tumor cells were positive for CD34 (strongly and diffusely) and STAT6. […] The expression of CD34 is strong in more than 80% of SFT tumors, but its expression can be absent in aggressive SFTs.

• #49 Solitary Fibrous Tumors: Symptoms, Causes & Treatment

  https://my.clevelandclinic.org/health/diseases/14945-solitary-fibrous-tumors

  Solitary fibrous tumors (SFTs) are soft tissue growths. […] Tests for solitary fibrous tumors depend on your symptoms and the tumor location. They may include: […] A biopsy to determine the tumor type and whether its cancerous. […] The WHO has a classification system for grading the severity of solitary fibrous tumors. […] Tumor grades for solitary fibrous tumors range from I to III: […] Healthcare providers perform surgery to remove a solitary fibrous tumor. […] If surgery isnt an option, you may get radiation therapy to shrink and destroy it. […] Most people do well after surgical removal of the tumor. […] In rare instances, a tumor may come back after treatment and become cancerous. […] Your healthcare provider will order more frequent imaging scans to check for tumor recurrence. […] Although rare, these tumors have the potential to turn into cancer and spread. […] Fortunately, your healthcare provider can surgically remove a solitary fibrous tumor to lower your cancer risk.

• #50 Clinical outcomes of solitary fibrous tumors and hemangiopericytomas and risk factors related to recurrence and survival based on the 2021 WHO classification of central nervous system tumors in: Journal of Neurosurgery Volume 140 Issue 1 (2023) Journals

  https://thejns.org/view/journals/j-neurosurg/140/1/article-p69.xml

  The authors aimed to explore the clinical outcomes and risk factors related to recurrence of and survival from solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) that were reclassified according to the 2021 WHO classification of central nervous system (CNS) tumors. […] The 2021 WHO classification of CNS tumors better predicted malignancy with different pathological grades, and in particular WHO grade 3 SFT had worse prognosis. Gross-total resection (GTR) can significantly prolong PFS and OS and should serve as the most important treatment method. Adjuvant RT was helpful for patients who underwent STR but not for patients who underwent GTR. […] The different pathological grades of SFT may significantly impact prognosis and indicate different treatment modalities for patients, so it is crucial to recognize the pathological grading of these tumors to improve patient outcomes.

• #51 Solitary fibrous tumour – Libre Pathology

  https://librepathology.org/wiki/Solitary_fibrous_tumour

  Solitary fibrous tumour. HE stain. LM spindle cells in a patternless pattern, hemangiopericytoma-like areas (staghorn vessels), keloid-like collagen bundles, +/-well-circumscribed (common) Subtypes benign (common), malignant (uncommon) IHC CD34 ~90% +ve, CD99 ~70% +ve, BCL2 ~50% +ve Site soft tissue – fibroblastic/myofibroblastic tumours, pleura […] May be benign or malignant; more commonly benign. […] Criteria for malignancy: Necrosis. Mitoses 4/10 HPF — definition suffers from HPFitis. Increased cellularity. Marked nuclear atypia. Infiltrative margin. […] STAT 6 positivity is very helpful in separating this tumor from its mimics.

• #52 Solitary fibrous tumor | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/solitary-fibrous-tumour?lang=us

  Lower risk solitary fibrous tumors tend to be smaller (10 cm) in size and occur in younger individuals. […] In contrast, high risk tumors tend to be larger at the time of diagnosis (10 cm), more commonly encountered in older individuals and have the expected histological features (increased cellularity, increased mitotic activity, nuclear pleomorphism, etc.) as well as necrosis and local infiltration. […] Metastasis rates can be as high as ~35% (range 25-45%) with late recurrence common. […] Optimal adjuvant therapy for this group is unknown, and close-interval follow-up is advised because there is an increased incidence of local recurrence.

• #53 Solitary fibrous tumor | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/solitary-fibrous-tumour?lang=us

  Lower risk solitary fibrous tumors tend to be smaller (10 cm) in size and occur in younger individuals. […] In contrast, high risk tumors tend to be larger at the time of diagnosis (10 cm), more commonly encountered in older individuals and have the expected histological features (increased cellularity, increased mitotic activity, nuclear pleomorphism, etc.) as well as necrosis and local infiltration. […] Metastasis rates can be as high as ~35% (range 25-45%) with late recurrence common. […] Optimal adjuvant therapy for this group is unknown, and close-interval follow-up is advised because there is an increased incidence of local recurrence.

• #54 Retroperitoneal Malignant Solitary Fibrous Tumor: A Case Report and Review of the Literature

  https://www.clinmedjournals.org/articles/ijpcr/international-journal-of-pathology-and-clinical-research-ijpcr-5-097.php?jid=ijpcr

  Solitary fibrous tumor is a rare soft-tissue neoplasm that is capable of metastasis of fibroblastic/myofibroblastic cell origin. […] The case was diagnosed as retroperitoneal solitary fibrous tumor. The tumor was compatible with the malignant category due to widespread necrosis, increased cellularity and high mitotic index. […] The definitive diagnosis of SFT is possible with histopathological examination. […] Immunohistochemistry is important in diagnosis. […] The tumor of our case had a diameter of 12 cm and it was above the threshold of 10 cm, which Shoubbege described as a risk factor. […] We reported our case as SFT with malignant histopathological features because of the presence of a high mitotic index (10/10 HPF), infiltrative border feature, large necrosis foci and vascular invasion. […] The most important prognostic factor is the adequacy of surgical resection.

• #55 Role of Immunohistochemistry in the Diagnosis of Solitary Fibrous Tumor, a Review

  https://ijp.iranpath.org/article_19723.html

  The MIB-1 index has been proposed as an acceptable criterion for prediction of aggressive behavior in CNS SFTs. […] Immunohistochemical markers are very important for the histopathologic diagnosis of this tumor; especially CD34, Bcl-2 and STAT-6. […] There are also consistently negative markers in this tumor which can be used according to the location.

• #56 Solitary fibrous tumor | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/solitary-fibrous-tumour?lang=us

  Lower risk solitary fibrous tumors tend to be smaller (10 cm) in size and occur in younger individuals. […] In contrast, high risk tumors tend to be larger at the time of diagnosis (10 cm), more commonly encountered in older individuals and have the expected histological features (increased cellularity, increased mitotic activity, nuclear pleomorphism, etc.) as well as necrosis and local infiltration. […] Metastasis rates can be as high as ~35% (range 25-45%) with late recurrence common. […] Optimal adjuvant therapy for this group is unknown, and close-interval follow-up is advised because there is an increased incidence of local recurrence.

• #57 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  However, a core needle biopsy or an open incisional biopsy and an immunohistochemical analysis are needed to confirm the diagnosis. […] The metastatic rate of SFTs is up to 35–45%. […] Furthermore, tumors classified primarily as benign may show malignant behavior many years after initial diagnosis. […] For this reason, patients require long-term observation, especially those with tumors greater than 10 cm. […] The presence of cells positive for desmin distinguishes tumors from desmoid. […] At the same time, actin-positive staining and myxoid parts represent nodular fasciitis. […] When SFTs differentiate from immunohistochemically similar tumors, STAT6 positive staining and the specific pattern of the vessels are crucial. […] The cornerstone of SFT pathogenesis is linked to the presence of NAB2-STAT6 gene fusion from the 12q13 chromosome.

• #58 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  However, a core needle biopsy or an open incisional biopsy and an immunohistochemical analysis are needed to confirm the diagnosis. […] The metastatic rate of SFTs is up to 35–45%. […] Furthermore, tumors classified primarily as benign may show malignant behavior many years after initial diagnosis. […] For this reason, patients require long-term observation, especially those with tumors greater than 10 cm. […] The presence of cells positive for desmin distinguishes tumors from desmoid. […] At the same time, actin-positive staining and myxoid parts represent nodular fasciitis. […] When SFTs differentiate from immunohistochemically similar tumors, STAT6 positive staining and the specific pattern of the vessels are crucial. […] The cornerstone of SFT pathogenesis is linked to the presence of NAB2-STAT6 gene fusion from the 12q13 chromosome.

• #59 Solitary fibrous tumor | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/solitary-fibrous-tumour?lang=us

  Lower risk solitary fibrous tumors tend to be smaller (10 cm) in size and occur in younger individuals. […] In contrast, high risk tumors tend to be larger at the time of diagnosis (10 cm), more commonly encountered in older individuals and have the expected histological features (increased cellularity, increased mitotic activity, nuclear pleomorphism, etc.) as well as necrosis and local infiltration. […] Metastasis rates can be as high as ~35% (range 25-45%) with late recurrence common. […] Optimal adjuvant therapy for this group is unknown, and close-interval follow-up is advised because there is an increased incidence of local recurrence.

• #60 Clinical outcomes of solitary fibrous tumors and hemangiopericytomas and risk factors related to recurrence and survival based on the 2021 WHO classification of central nervous system tumors in: Journal of Neurosurgery Volume 140 Issue 1 (2023) Journals

  https://thejns.org/view/journals/j-neurosurg/140/1/article-p69.xml

  In multivariate Cox regression analysis, subtotal resection (STR) (HR 4.648, 95% CI 2.6018.304, p 0.001), tumor located in the parasagittal or parafalx region (HR 2.105, 95% CI 1.0994.033, p = 0.025), tumor in the vertebrae (HR 3.352, 95% CI 1.2289.148, p = 0.018), WHO grade 2 SFT (HR 2.579, 95% CI 1.3434.953, p = 0.004), and WHO grade 3 SFT (HR 5.814, 95% CI 2.88711.712, p 0.001) were significantly associated with shortened PFS, whereas STR (HR 3.217, 95% CI 1.4357.210, p = 0.005) and WHO grade 3 SFT (HR 3.433, 95% CI 1.3248.901, p = 0.011) were significantly associated with shortened OS. […] The average (95% CI) time to tumor recurrence was 93.5 (78.1108.9) months, and the median (95% CI) time was 77 (64.689.4) months after initial diagnosis, with 5- and 10-year PFS rates of 70.2% and 22.4%, respectively.

• #61

  https://link.springer.com/article/10.1007/s00701-024-06304-7

  Solitary fibrous tumors (SFTs) are a rare type of mesenchymal tumors. The World Health Organization reclassified SFTs in 2021. Currently, guidelines concerning treatment and follow-up are lacking. […] Although rare, SFT should be included in the differential diagnosis of intracranial tumors with extra-axial growth patterns. The current histological grade according to the WHO 2021 does not seem to account for local recurrence rate or systemic metastasis. When a solitary fibrous tumor is presumed, gross total resection is the recommended treatment. Lifelong patient follow-up is necessary due to the risk of delayed recurrence and distant metastasis, even after gross-total resection. We would advocate for the use of CT thorax-abdomen or full body PET in the detection of systemic metastases at diagnosis and during follow-up, however optimal intervals remain unclear.

• #62 Nuclear expression of STAT6 distinguishes solitary fibrous tumor from histologic mimics | Modern Pathology

  https://www.nature.com/articles/modpathol2013164

  Solitary fibrous tumor (SFT) is composed of spindled to ovoid cells in a patternless architecture with prominent stromal collagen and hemangiopericytoma-like vessels. […] SFT can sometimes be difficult to distinguish from other benign mesenchymal tumors and sarcomas. […] The most characteristic (albeit nonspecific) immunohistochemical finding in SFT is CD34 expression. […] A NAB2STAT6 gene fusion, resulting in a chimeric protein in which a repressor domain of NGFI-A binding protein 2 (EGR1 binding protein 2) (NAB2) is replaced with a carboxy-terminal transactivation domain from signal transducer and activator of transcription 6, interleukin-4 induced (STAT6), was recently identified as a consistent finding in SFT. […] Nuclear expression of the carboxy terminal part of STAT6 is a consistent finding in SFT of the meninges (so-called meningeal hemangiopericytoma).

• #63 The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior | Diagnostic Pathology | Full Text

  https://diagnosticpathology.biomedcentral.com/articles/10.1186/s13000-021-01095-2

  Solitary Fibrous Tumor (SFT) is a distinct soft tissue neoplasm associated with NAB2-STAT6 gene fusion. It can involve a number of anatomic sites and exhibits a wide spectrum of histological features. […] The management and prognosis of SFT differs from its malignant mimics and correct diagnosis is therefore important. […] Although SFT expresses a distinct immunohistochemical (IHC) profile, the classic histomorphological and IHC profile is not seen in all cases and diagnosis can be challenging. […] NAB2-STAT6 gene fusion has recently emerged as a sensitive and specific molecular marker and its IHC surrogate marker signal transducer and activator of transcription 6 (STAT6) has also shown significant sensitivity and specificity. […] This review will focus on describing the diversity of histological features of SFT, differential diagnoses and discussing the features helpful in distinguishing SFT from its histological mimics.

• #64 Diagnostic challenges and treatment options in patients with solitary fibrous tumor: A single-center observational study

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9583656/

  Solitary fibrous tumor (SFT) is an extremely rare disease with a high misdiagnosis rate and a potentially malignant biologic nature. […] In three patients, the preoperative diagnosis did not correlate with the definitive histology of SFT. […] The diagnosis of SFT is usually made upon a combination of imaging techniques, pretreatment biopsy, and histopathological evaluation. […] Our data indicated that the preoperative misdiagnosis rate was high and corroborated that of previously published studies by Chu et al. and Kim et al. […] In 17% of our patients, the preoperative diagnosis did not match the postoperative histology. […] The need for obtaining negative resection margins stems from the fact that SFTs have uncertain biological behavior and a high rate of local recurrences. […] The mainstay of SFT treatment remains radical surgery, where obtaining negative resection margins is the most important factor preventing the disease recurrence. […] While radiotherapy alone can significantly improve the overall survival of patients, we believe that more therapies, mainly targeted therapy and immunotherapy, should become a part of the sophisticated therapeutic scheme in SFT.

• #65 Diagnostic challenges and treatment options in patients with solitary fibrous tumor: A single-center observational study

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9583656/

  Solitary fibrous tumor (SFT) is an extremely rare disease with a high misdiagnosis rate and a potentially malignant biologic nature. […] In three patients, the preoperative diagnosis did not correlate with the definitive histology of SFT. […] The diagnosis of SFT is usually made upon a combination of imaging techniques, pretreatment biopsy, and histopathological evaluation. […] Our data indicated that the preoperative misdiagnosis rate was high and corroborated that of previously published studies by Chu et al. and Kim et al. […] In 17% of our patients, the preoperative diagnosis did not match the postoperative histology. […] The need for obtaining negative resection margins stems from the fact that SFTs have uncertain biological behavior and a high rate of local recurrences. […] The mainstay of SFT treatment remains radical surgery, where obtaining negative resection margins is the most important factor preventing the disease recurrence. […] While radiotherapy alone can significantly improve the overall survival of patients, we believe that more therapies, mainly targeted therapy and immunotherapy, should become a part of the sophisticated therapeutic scheme in SFT.

• #66 Solitary fibrous tumor of the dura | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/solitary-fibrous-tumour-of-the-dura?lang=us

  Solitary fibrous tumors of the dura are rare dural masses, histologically identical to solitary fibrous tumors found elsewhere and encompassing hemangiopericytomas (previously thought of as separate diagnoses). This was reflected in the 4th edition WHO classification of CNS tumors (2016). […] Solitary fibrous tumors are composed of spindle cells thought to be of mesenchymal origin. They usually occur in middle-aged individuals and symptoms depend on the size of the mass and its location. […] On imaging, these tumors are similar to meningiomas, appearing as extra-axial well-circumscribed solid masses with vivid contrast enhancement. […] Clinical presentation is nonspecific and identical to other dural masses (e.g. meningioma). Symptoms depend on the size of the mass and its location. Headache is the most common presenting complaint. […] The most useful feature that helps in making a preoperative diagnosis is the propensity for low grade solitary fibrous tumor to be low signal on T2.

• #67 A solitary fibrous tumor mimicking a peripheral nerve sheath tumor: Case report and review of the literature

  https://www.oatext.com/a-solitary-fibrous-tumor-mimicking-a-peripheral-nerve-sheath-tumor-case-report-and-review-of-the-literature.php

  Solitary fibrous tumors (SFT) are commonly found in the thorax, however extrathoracic locations may present with symptoms of nerve compression. […] While the patients mass was initially thought to be a peripheral nerve sheath tumor, pathology revealed that it was a SFT. We highlight the importance of tissue diagnosis and complete resection for treatment. […] We present the case of a mass intimately associated with the S1 nerve that was initially diagnosed as a peripheral nerve sheath tumor on imaging. Permanent pathology, however, revealed a SFT. […] SFTs may initially be diagnosed with CT or MR imaging, however investigation of the tissue histologically is required for diagnosis. […] Due to its intimate association with the S1 nerve, we favored peripheral nerve sheath tumor as our pre-operative diagnosis based on the CT and MR imaging.

• #68 A solitary fibrous tumor mimicking a peripheral nerve sheath tumor: Case report and review of the literature

  https://www.oatext.com/a-solitary-fibrous-tumor-mimicking-a-peripheral-nerve-sheath-tumor-case-report-and-review-of-the-literature.php

  Surgical resection is the mainstay of treatment for SFTs, including extrathoracic SFTs. […] While rare, solitary fibrous tumors can be found in extrathoracic sites such as the pelvis. In this report, we review the case of a patient who presented with signs and symptoms attributable to S1 nerve root compression with imaging demonstrating a mass abutting the S1 nerve root. It was initially thought to be a peripheral nerve sheath tumor, however permanent pathology revealed that it was a SFT. We highlight the importance of tissue diagnosis and complete resection for treatment.

• #69 Imaging, pathology, and diagnosis of solitary fibrous tumor of the pancreas: A case report and review of literature

  https://www.wjgnet.com/2307-8960/full/v12/i5/995.htm

  A solitary fibrous tumor (SFT) is often located in the pleura, while SFT of the pancreas is extremely rare. […] The final diagnosis depends on histopathology and immunohistochemistry. […] CT and pathological histology have diagnostic value for pancreatic tumors. Endoscopic puncture biopsy under ultrasound can help diagnose pancreatic masses that cannot be diagnosed preoperatively. […] Histopathology and immunohistochemistry are the gold standards for diagnosis. We recommend ultrasound endoscopic aspiration biopsy for space-occupying pancreatic lesions that cannot be diagnosed on imaging. […] A definitive diagnosis relies on histopathology and immunohistochemistry. In cases where the tumor is found in the pancreas, and the diagnosis cannot be confirmed, it is recommended to obtain histopathology with ultrasound aspiration. […] Because of the non-specific clinical symptoms and radiological features of SFT of the pancreas, the diagnosis is challenging with preoperative radiological and laboratory examinations alone.

• #70 Imaging, pathology, and diagnosis of solitary fibrous tumor of the pancreas: A case report and review of literature

  https://www.wjgnet.com/2307-8960/full/v12/i5/995.htm

  A solitary fibrous tumor (SFT) is often located in the pleura, while SFT of the pancreas is extremely rare. […] The final diagnosis depends on histopathology and immunohistochemistry. […] CT and pathological histology have diagnostic value for pancreatic tumors. Endoscopic puncture biopsy under ultrasound can help diagnose pancreatic masses that cannot be diagnosed preoperatively. […] Histopathology and immunohistochemistry are the gold standards for diagnosis. We recommend ultrasound endoscopic aspiration biopsy for space-occupying pancreatic lesions that cannot be diagnosed on imaging. […] A definitive diagnosis relies on histopathology and immunohistochemistry. In cases where the tumor is found in the pancreas, and the diagnosis cannot be confirmed, it is recommended to obtain histopathology with ultrasound aspiration. […] Because of the non-specific clinical symptoms and radiological features of SFT of the pancreas, the diagnosis is challenging with preoperative radiological and laboratory examinations alone.

• #71 The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior | Diagnostic Pathology | Full Text

  https://diagnosticpathology.biomedcentral.com/articles/10.1186/s13000-021-01095-2

  Solitary Fibrous Tumor (SFT) is a distinct soft tissue neoplasm associated with NAB2-STAT6 gene fusion. It can involve a number of anatomic sites and exhibits a wide spectrum of histological features. […] The management and prognosis of SFT differs from its malignant mimics and correct diagnosis is therefore important. […] Although SFT expresses a distinct immunohistochemical (IHC) profile, the classic histomorphological and IHC profile is not seen in all cases and diagnosis can be challenging. […] NAB2-STAT6 gene fusion has recently emerged as a sensitive and specific molecular marker and its IHC surrogate marker signal transducer and activator of transcription 6 (STAT6) has also shown significant sensitivity and specificity. […] This review will focus on describing the diversity of histological features of SFT, differential diagnoses and discussing the features helpful in distinguishing SFT from its histological mimics.

• #72 Solitary fibrous tumor – Davanzo – Translational Gastroenterology and Hepatology

  https://tgh.amegroups.org/article/view/4708/html

  Solitary fibrous tumor (SFT) is a rare tumor of mesenchymal origin that account for less than 2% of all soft tissue masses. […] Over the last several decades, sustained advances through research and technology have led to more reliable methods for differentiating this distinct soft tissue tumor. […] Advances specifically in immunohistochemistry and molecular diagnostics have identified CD34 as the most consistent marker in SFT, however even this lacks specificity to conclusively narrow down the broad differential for exact identification. […] More recently the discovery of the NAB2-STAT6 fusion gene has led to more precise diagnosis of SFT. […] The work up and diagnosis of SFT is analogous to many other soft tissue masses. […] A pre-treatment biopsy to diagnose and grade the mass is ideal.

• #73 The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior | Diagnostic Pathology | Full Text

  https://diagnosticpathology.biomedcentral.com/articles/10.1186/s13000-021-01095-2

  Accurate diagnosis is essential for appropriate treatment and management of SFTs. NAB2-STAT6 gene fusion and its IHC expression are consistently observed in these tumors. Immunohistochemistry is the most sensitive and specific means of diagnosing SFT and is practical and economical as well. […] Molecular studies require expensive equipment and well-trained staff which reduces their practicality and feasibility in resource limited laboratories of developing countries. Molecular testing may be helpful where IHC results are ambiguous. Thorough knowledge about the morphological variations of SFTs and correlation with clinical, IHC and molecular features are helpful in avoiding misdiagnosis.

• #74 The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior | Diagnostic Pathology | Full Text

  https://diagnosticpathology.biomedcentral.com/articles/10.1186/s13000-021-01095-2

  Accurate diagnosis is essential for appropriate treatment and management of SFTs. NAB2-STAT6 gene fusion and its IHC expression are consistently observed in these tumors. Immunohistochemistry is the most sensitive and specific means of diagnosing SFT and is practical and economical as well. […] Molecular studies require expensive equipment and well-trained staff which reduces their practicality and feasibility in resource limited laboratories of developing countries. Molecular testing may be helpful where IHC results are ambiguous. Thorough knowledge about the morphological variations of SFTs and correlation with clinical, IHC and molecular features are helpful in avoiding misdiagnosis.

• #75 The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior | Diagnostic Pathology | Full Text

  https://diagnosticpathology.biomedcentral.com/articles/10.1186/s13000-021-01095-2

  Accurate diagnosis is essential for appropriate treatment and management of SFTs. NAB2-STAT6 gene fusion and its IHC expression are consistently observed in these tumors. Immunohistochemistry is the most sensitive and specific means of diagnosing SFT and is practical and economical as well. […] Molecular studies require expensive equipment and well-trained staff which reduces their practicality and feasibility in resource limited laboratories of developing countries. Molecular testing may be helpful where IHC results are ambiguous. Thorough knowledge about the morphological variations of SFTs and correlation with clinical, IHC and molecular features are helpful in avoiding misdiagnosis.

• #76 Solitary fibrous tumor – Davanzo – Translational Gastroenterology and Hepatology

  https://tgh.amegroups.org/article/view/4708/html

  Molecular genetic analysis has proven vital in further differentiating soft tissue masses for diagnosis. SFT has recently been associated with a NAB2-STAT6 gene fusion product that has proven to be highly specific and sensitive for SFT. […] Strong nuclear STAT6 IHC staining has been used to reliably differentiate SFT from other soft tissue tumors, tumors of the head and neck, gynecologic tract and prostate. […] Recently, multiple groups discovered a gene fusion product between NAB2 and STAT6, which is a highly sensitive and specific marker for SFT and is considered the molecular hallmark of SFT. […] The 2013 World Health Organization classification of soft tissue sarcomas helped further differentiate many sarcomas with SFT being classified as a fibroblastic/myofibroblastic tumor. […] Given the rarity of SFT and mostly retrospective data from small cases series, there is still much progress to be made. […] While surgical resection is the mainstay of treatment and provides favorable outcomes for resectable disease, radiation and chemotherapy may have potential roles in the treatment algorithm.

• #77 Diagnostic challenges and treatment options in patients with solitary fibrous tumor: A single-center observational study

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9583656/

  Solitary fibrous tumor (SFT) is an extremely rare disease with a high misdiagnosis rate and a potentially malignant biologic nature. […] In three patients, the preoperative diagnosis did not correlate with the definitive histology of SFT. […] The diagnosis of SFT is usually made upon a combination of imaging techniques, pretreatment biopsy, and histopathological evaluation. […] Our data indicated that the preoperative misdiagnosis rate was high and corroborated that of previously published studies by Chu et al. and Kim et al. […] In 17% of our patients, the preoperative diagnosis did not match the postoperative histology. […] The need for obtaining negative resection margins stems from the fact that SFTs have uncertain biological behavior and a high rate of local recurrences. […] The mainstay of SFT treatment remains radical surgery, where obtaining negative resection margins is the most important factor preventing the disease recurrence. […] While radiotherapy alone can significantly improve the overall survival of patients, we believe that more therapies, mainly targeted therapy and immunotherapy, should become a part of the sophisticated therapeutic scheme in SFT.

• #78 Diagnostic challenges and treatment options in patients with solitary fibrous tumor: A single-center observational study

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9583656/

  Solitary fibrous tumor (SFT) is an extremely rare disease with a high misdiagnosis rate and a potentially malignant biologic nature. […] In three patients, the preoperative diagnosis did not correlate with the definitive histology of SFT. […] The diagnosis of SFT is usually made upon a combination of imaging techniques, pretreatment biopsy, and histopathological evaluation. […] Our data indicated that the preoperative misdiagnosis rate was high and corroborated that of previously published studies by Chu et al. and Kim et al. […] In 17% of our patients, the preoperative diagnosis did not match the postoperative histology. […] The need for obtaining negative resection margins stems from the fact that SFTs have uncertain biological behavior and a high rate of local recurrences. […] The mainstay of SFT treatment remains radical surgery, where obtaining negative resection margins is the most important factor preventing the disease recurrence. […] While radiotherapy alone can significantly improve the overall survival of patients, we believe that more therapies, mainly targeted therapy and immunotherapy, should become a part of the sophisticated therapeutic scheme in SFT.

• #79 Solitary Fibrous Tumor – EyeWiki

  https://eyewiki.org/Solitary_Fibrous_Tumor

  The primary management of solitary fibrous tumors is complete surgical excision. […] En bloc complete surgical excision is the treatment of choice given the tendency for recurrence and possible malignant degeneration in tumors that are not primarily excised. […] Complete surgical excision of the lesion or exenteration of infiltrating lesions are the recommended surgical treatments. […] Prognosis is excellent for tumors that are completely excised. Of the cases described in the literature, about 75% of solitary fibrous tumors display a benign course; and 25% showing invasion to adjacent tissues, recurrence, or distant metastasis.

• #80

  http://waocp.com/journal/index.php/apjcc/article/view/1301

  Discovery of nuclear expression of STAT6 protein in SFT is the most sensitive and specific marker for diagnosis of conventional and malignant SFT. […] In our case report,finally, the diagnosis of SFT was established based on the expression of IHC for STAT6 and CD34. […] Surgical resection is the mainstay treatment of localized SFT. […] To attain better local control of disease,adjuvant therapy in the form of External beam radiotherapy is recommended in malignant SFT with various studies on retrospective analysis showed a clear trend toward better local control. […] In conclusion, SFT is a rare thoracic tumor which can be recognized on usual histomorphology and immunophenotypic profile with mediastinal SFT being a very rare entity.

• #81 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  However, a core needle biopsy or an open incisional biopsy and an immunohistochemical analysis are needed to confirm the diagnosis. […] The metastatic rate of SFTs is up to 35–45%. […] Furthermore, tumors classified primarily as benign may show malignant behavior many years after initial diagnosis. […] For this reason, patients require long-term observation, especially those with tumors greater than 10 cm. […] The presence of cells positive for desmin distinguishes tumors from desmoid. […] At the same time, actin-positive staining and myxoid parts represent nodular fasciitis. […] When SFTs differentiate from immunohistochemically similar tumors, STAT6 positive staining and the specific pattern of the vessels are crucial. […] The cornerstone of SFT pathogenesis is linked to the presence of NAB2-STAT6 gene fusion from the 12q13 chromosome.

• #82 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  The specificity of NAB2-STAT6 fusion allows the usage of STAT6 immunochemistry (IHC) in the identification of SFTs. […] A recent study suggested the presence of neuroendocrine markers in SFT, such as INSM1 (positive in 35.7%), synaptophysin, CD56, and CD57. […] The latest studies suggest that antiangiogenic therapies should be considered after first-line treatment, with the exclusion of dedifferentiated SFTs. […] In cases of unresectable disease, only radiotherapy or radio-chemotherapy may significantly ensure long-term local control of primary and metastatic lesions. […] The role of perioperative radiotherapy in localized SFTs was the subject of some retrospective studies. […] The efficacy of chemotherapy on SFTs is limited. […] However, there are examples of successful preoperative systemic treatment. […] The latest trial suggests that pazopanib treatment has a potentially beneficial effect on unresectable malignant SFTs.

• #83 Clinical outcomes of solitary fibrous tumors and hemangiopericytomas and risk factors related to recurrence and survival based on the 2021 WHO classification of central nervous system tumors in: Journal of Neurosurgery Volume 140 Issue 1 (2023) Journals

  https://thejns.org/view/journals/j-neurosurg/140/1/article-p69.xml

  The authors aimed to explore the clinical outcomes and risk factors related to recurrence of and survival from solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) that were reclassified according to the 2021 WHO classification of central nervous system (CNS) tumors. […] The 2021 WHO classification of CNS tumors better predicted malignancy with different pathological grades, and in particular WHO grade 3 SFT had worse prognosis. Gross-total resection (GTR) can significantly prolong PFS and OS and should serve as the most important treatment method. Adjuvant RT was helpful for patients who underwent STR but not for patients who underwent GTR. […] The different pathological grades of SFT may significantly impact prognosis and indicate different treatment modalities for patients, so it is crucial to recognize the pathological grading of these tumors to improve patient outcomes.

• #84 Clinical outcomes of solitary fibrous tumors and hemangiopericytomas and risk factors related to recurrence and survival based on the 2021 WHO classification of central nervous system tumors in: Journal of Neurosurgery Volume 140 Issue 1 (2023) Journals

  https://thejns.org/view/journals/j-neurosurg/140/1/article-p69.xml

  The authors aimed to explore the clinical outcomes and risk factors related to recurrence of and survival from solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) that were reclassified according to the 2021 WHO classification of central nervous system (CNS) tumors. […] The 2021 WHO classification of CNS tumors better predicted malignancy with different pathological grades, and in particular WHO grade 3 SFT had worse prognosis. Gross-total resection (GTR) can significantly prolong PFS and OS and should serve as the most important treatment method. Adjuvant RT was helpful for patients who underwent STR but not for patients who underwent GTR. […] The different pathological grades of SFT may significantly impact prognosis and indicate different treatment modalities for patients, so it is crucial to recognize the pathological grading of these tumors to improve patient outcomes.

• #85 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  The specificity of NAB2-STAT6 fusion allows the usage of STAT6 immunochemistry (IHC) in the identification of SFTs. […] A recent study suggested the presence of neuroendocrine markers in SFT, such as INSM1 (positive in 35.7%), synaptophysin, CD56, and CD57. […] The latest studies suggest that antiangiogenic therapies should be considered after first-line treatment, with the exclusion of dedifferentiated SFTs. […] In cases of unresectable disease, only radiotherapy or radio-chemotherapy may significantly ensure long-term local control of primary and metastatic lesions. […] The role of perioperative radiotherapy in localized SFTs was the subject of some retrospective studies. […] The efficacy of chemotherapy on SFTs is limited. […] However, there are examples of successful preoperative systemic treatment. […] The latest trial suggests that pazopanib treatment has a potentially beneficial effect on unresectable malignant SFTs.

• #86 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  The specificity of NAB2-STAT6 fusion allows the usage of STAT6 immunochemistry (IHC) in the identification of SFTs. […] A recent study suggested the presence of neuroendocrine markers in SFT, such as INSM1 (positive in 35.7%), synaptophysin, CD56, and CD57. […] The latest studies suggest that antiangiogenic therapies should be considered after first-line treatment, with the exclusion of dedifferentiated SFTs. […] In cases of unresectable disease, only radiotherapy or radio-chemotherapy may significantly ensure long-term local control of primary and metastatic lesions. […] The role of perioperative radiotherapy in localized SFTs was the subject of some retrospective studies. […] The efficacy of chemotherapy on SFTs is limited. […] However, there are examples of successful preoperative systemic treatment. […] The latest trial suggests that pazopanib treatment has a potentially beneficial effect on unresectable malignant SFTs.

• #87

  https://link.springer.com/article/10.1007/s10555-024-10204-8

  Solitary fibrous tumor (SFT) is a rare fibroblastic mesenchymal neoplasm. […] Diagnostic methods play a crucial role in SFT clinical practice and basic research, including RT-PCR, next-generation sequencing (NGS), FISH, immunohistochemistry (IHC), and Western blot analysis, each with distinct capabilities and limitations. […] Diagnostic methods are crucial in SFT research and clinics, including RT-PCR, NGS, FISH, IHC, and Western blot analysis. Each of these offers distinct capabilities and challenges. RT-PCR is adept at detecting known fusions, while NGS provides comprehensive genomic insights. FISH reveals NAB2-STAT6 gene fusion, while IHC and Western blot demonstrate significant value in NAB2-STAT6 protein assessment. […] In this review, we summarize the latest developments in the clinical characteristics and molecular mechanisms of SFT, aiming to provide an update on the diagnostic methods and potential breakthroughs in treatments.

• #88 Solitary fibrous tumor – Davanzo – Translational Gastroenterology and Hepatology

  https://tgh.amegroups.org/article/view/4708/html

  Solitary fibrous tumor (SFT) is a rare tumor of mesenchymal origin that account for less than 2% of all soft tissue masses. […] Over the last several decades, sustained advances through research and technology have led to more reliable methods for differentiating this distinct soft tissue tumor. […] Advances specifically in immunohistochemistry and molecular diagnostics have identified CD34 as the most consistent marker in SFT, however even this lacks specificity to conclusively narrow down the broad differential for exact identification. […] More recently the discovery of the NAB2-STAT6 fusion gene has led to more precise diagnosis of SFT. […] The work up and diagnosis of SFT is analogous to many other soft tissue masses. […] A pre-treatment biopsy to diagnose and grade the mass is ideal.

• #89 Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

  https://www.mdpi.com/2072-6694/15/24/5854

  The specificity of NAB2-STAT6 fusion allows the usage of STAT6 immunochemistry (IHC) in the identification of SFTs. […] A recent study suggested the presence of neuroendocrine markers in SFT, such as INSM1 (positive in 35.7%), synaptophysin, CD56, and CD57. […] The latest studies suggest that antiangiogenic therapies should be considered after first-line treatment, with the exclusion of dedifferentiated SFTs. […] In cases of unresectable disease, only radiotherapy or radio-chemotherapy may significantly ensure long-term local control of primary and metastatic lesions. […] The role of perioperative radiotherapy in localized SFTs was the subject of some retrospective studies. […] The efficacy of chemotherapy on SFTs is limited. […] However, there are examples of successful preoperative systemic treatment. […] The latest trial suggests that pazopanib treatment has a potentially beneficial effect on unresectable malignant SFTs.

• #90 Solitary fibrous tumor – Davanzo – Translational Gastroenterology and Hepatology

  https://tgh.amegroups.org/article/view/4708/html

  Molecular genetic analysis has proven vital in further differentiating soft tissue masses for diagnosis. SFT has recently been associated with a NAB2-STAT6 gene fusion product that has proven to be highly specific and sensitive for SFT. […] Strong nuclear STAT6 IHC staining has been used to reliably differentiate SFT from other soft tissue tumors, tumors of the head and neck, gynecologic tract and prostate. […] Recently, multiple groups discovered a gene fusion product between NAB2 and STAT6, which is a highly sensitive and specific marker for SFT and is considered the molecular hallmark of SFT. […] The 2013 World Health Organization classification of soft tissue sarcomas helped further differentiate many sarcomas with SFT being classified as a fibroblastic/myofibroblastic tumor. […] Given the rarity of SFT and mostly retrospective data from small cases series, there is still much progress to be made. […] While surgical resection is the mainstay of treatment and provides favorable outcomes for resectable disease, radiation and chemotherapy may have potential roles in the treatment algorithm.

• #91 The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior | Diagnostic Pathology | Full Text

  https://diagnosticpathology.biomedcentral.com/articles/10.1186/s13000-021-01095-2

  Solitary Fibrous Tumor (SFT) is a distinct soft tissue neoplasm associated with NAB2-STAT6 gene fusion. It can involve a number of anatomic sites and exhibits a wide spectrum of histological features. […] The management and prognosis of SFT differs from its malignant mimics and correct diagnosis is therefore important. […] Although SFT expresses a distinct immunohistochemical (IHC) profile, the classic histomorphological and IHC profile is not seen in all cases and diagnosis can be challenging. […] NAB2-STAT6 gene fusion has recently emerged as a sensitive and specific molecular marker and its IHC surrogate marker signal transducer and activator of transcription 6 (STAT6) has also shown significant sensitivity and specificity. […] This review will focus on describing the diversity of histological features of SFT, differential diagnoses and discussing the features helpful in distinguishing SFT from its histological mimics.

• #92 A case of fat-forming solitary fibrous tumor that is prone to be confused with liposarcoma | Diagnostic Pathology | Full Text

  https://diagnosticpathology.biomedcentral.com/articles/10.1186/s13000-024-01463-8

  Based on the observed histological features and immunophenotype, the accurate diagnosis of fat-forming SFT was established, and other differential diagnoses such as liposarcoma, angiomyolipoma, and spindle cell lipoma were ruled out. […] The strong and diffuse STAT6 immunoreactivity is a key diagnostic factor in this case. […] Therefore, the detection of CDK4/MDM2 by FISH or immunohistochemistry is necessary to exclude dedifferentiated liposarcoma. […] The diagnosis of fat-forming SFT requires an integrated approach due to its rarity; otherwise, the correct diagnosis could be easily missed, leading to unnecessary treatments for the patient.

• #93 Nuclear expression of STAT6 distinguishes solitary fibrous tumor from histologic mimics | Modern Pathology

  https://www.nature.com/articles/modpathol2013164

  The discovery of a recurrent gene fusion by whole-exome and transcriptome sequencing is a novel method of detecting translocation-associated sarcomas. […] This adds to the expanding group of markers for soft tissue tumors identified through molecular genetic methods. […] Nuclear expression of STAT6 is found in nearly all cases of SFT and is very limited in other soft tissue neoplasms. STAT6 is therefore a highly sensitive and almost perfectly specific immunohistochemical marker for SFT, and can be helpful to distinguish this tumor type from histologic mimics.

• #94 Nuclear expression of STAT6 distinguishes solitary fibrous tumor from histologic mimics | Modern Pathology

  https://www.nature.com/articles/modpathol2013164

  We investigated STAT6 expression by immunohistochemistry in SFTs and other soft tissue tumors arising outside the central nervous system to validate the diagnostic utility of this novel marker. […] Fifty-nine of 60 SFT cases (98%) showed nuclear expression of STAT6, which was usually diffuse and intense. […] In conclusion, STAT6 is a highly sensitive and almost perfectly specific immunohistochemical marker for SFT and can be helpful to distinguish this tumor type from histologic mimics. […] Although in most cases the diagnosis of SFT is relatively straightforward, some tumors may mimic other benign mesenchymal tumors or sarcomas, and a subset of SFTs lack expression of CD34. […] In this study, we investigated STAT6 protein expression by immunohistochemistry in SFT and histologic mimics to validate the utility of STAT6 as a diagnostic marker.

• #95 Clinical outcomes of solitary fibrous tumors and hemangiopericytomas and risk factors related to recurrence and survival based on the 2021 WHO classification of central nervous system tumors in: Journal of Neurosurgery Volume 140 Issue 1 (2023) Journals

  https://thejns.org/view/journals/j-neurosurg/140/1/article-p69.xml

  The relationships of the prior WHO grades with PFS and OS are controversial. Several studies showed no significant association between WHO grade and PFS or OS. […] Our results indicated that there was a significant association between WHO grade and PFS. The grade 2 SFT group had shorter PFS than the grade 1 SFT group, whereas the grade 3 SFT group had shorter PFS than the grade 2 SFT group. Furthermore, patients with grade 3 SFT had significantly shorter OS compared with patients with grade 1 SFT in multivariate Cox regression analysis.

• #96

  https://link.springer.com/article/10.1007/s00701-024-06304-7

  Solitary fibrous tumors (SFTs) are a rare type of mesenchymal tumors. The World Health Organization reclassified SFTs in 2021. Currently, guidelines concerning treatment and follow-up are lacking. […] Although rare, SFT should be included in the differential diagnosis of intracranial tumors with extra-axial growth patterns. The current histological grade according to the WHO 2021 does not seem to account for local recurrence rate or systemic metastasis. When a solitary fibrous tumor is presumed, gross total resection is the recommended treatment. Lifelong patient follow-up is necessary due to the risk of delayed recurrence and distant metastasis, even after gross-total resection. We would advocate for the use of CT thorax-abdomen or full body PET in the detection of systemic metastases at diagnosis and during follow-up, however optimal intervals remain unclear.

• #97 Diagnostic challenges and treatment options in patients with solitary fibrous tumor: A single-center observational study

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9583656/

  Solitary fibrous tumor (SFT) is an extremely rare disease with a high misdiagnosis rate and a potentially malignant biologic nature. […] In three patients, the preoperative diagnosis did not correlate with the definitive histology of SFT. […] The diagnosis of SFT is usually made upon a combination of imaging techniques, pretreatment biopsy, and histopathological evaluation. […] Our data indicated that the preoperative misdiagnosis rate was high and corroborated that of previously published studies by Chu et al. and Kim et al. […] In 17% of our patients, the preoperative diagnosis did not match the postoperative histology. […] The need for obtaining negative resection margins stems from the fact that SFTs have uncertain biological behavior and a high rate of local recurrences. […] The mainstay of SFT treatment remains radical surgery, where obtaining negative resection margins is the most important factor preventing the disease recurrence. […] While radiotherapy alone can significantly improve the overall survival of patients, we believe that more therapies, mainly targeted therapy and immunotherapy, should become a part of the sophisticated therapeutic scheme in SFT.

• #98 Solitary Fibrous Tumor – EyeWiki

  https://eyewiki.org/Solitary_Fibrous_Tumor

  The primary management of solitary fibrous tumors is complete surgical excision. […] En bloc complete surgical excision is the treatment of choice given the tendency for recurrence and possible malignant degeneration in tumors that are not primarily excised. […] Complete surgical excision of the lesion or exenteration of infiltrating lesions are the recommended surgical treatments. […] Prognosis is excellent for tumors that are completely excised. Of the cases described in the literature, about 75% of solitary fibrous tumors display a benign course; and 25% showing invasion to adjacent tissues, recurrence, or distant metastasis.

• #99

  https://link.springer.com/article/10.1007/s10555-024-10204-8

  Solitary fibrous tumor (SFT) is a rare fibroblastic mesenchymal neoplasm. […] Diagnostic methods play a crucial role in SFT clinical practice and basic research, including RT-PCR, next-generation sequencing (NGS), FISH, immunohistochemistry (IHC), and Western blot analysis, each with distinct capabilities and limitations. […] Diagnostic methods are crucial in SFT research and clinics, including RT-PCR, NGS, FISH, IHC, and Western blot analysis. Each of these offers distinct capabilities and challenges. RT-PCR is adept at detecting known fusions, while NGS provides comprehensive genomic insights. FISH reveals NAB2-STAT6 gene fusion, while IHC and Western blot demonstrate significant value in NAB2-STAT6 protein assessment. […] In this review, we summarize the latest developments in the clinical characteristics and molecular mechanisms of SFT, aiming to provide an update on the diagnostic methods and potential breakthroughs in treatments.

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