Features Of Solitary Fibrous Tumor Research Articles

Clinical analysis of 12 cases of solitary fibrous tumors in nasal cavity, sinuses and skull base

Objective:To summarize and analyze the clinical manifestations, diagnosis and management and prognostic features of solitary fibrous tumor（SFT） in nasal cavity, sinus and skull base. Methods:The clinical data of 12 patients with STF from nasal cavity, sinus and cranial base admitted to the Affiliated Hospital of Qingdao University from April 2014 to January 2022 were retrospectively analyzed, including 4 patients admitted to the department of Otolaryngology head and neck surgery and 8 patients admitted to the department of skull base surgery The clinical characteristics, diagnosis, management and prognosis were analyzed. Results:Twelve patients were included in this research, including 7 males and 5 females. All patients received surgical treatment, and 4 patients also received postoperative adjuvant chemoradiotherapy. After follow-up for 12-60 months, 4 patients with adjuvant radiotherapy and chemotherapy had a good prognosis, and among 8 patients who did not receive radiotherapy and chemotherapy, 6 patients had good prognosis and 2 patients showed relapse. Four patients with a history of recurrence of SFT after surgery were admitted to our hospital for surgical treatment, in which 1 patient had relapse after surgery, and none had metastasis. Nasal cavity and sinus to skull base SFT is rare. The most effective treatment for this disease is surgical resection, and postoperative adjuvant chemoradiation and long-term follow-up can achieve a better prognosis. En bloc resection is the key to treatment success.

Multimodal Imaging of Solitary Fibrous Tumor in the CNS, Head and Neck, and Spine, with Pathologic Correlation

Solitary fibrous tumor is a rare mesenchymal neoplasm arising from the serosal membranes, dura, and deep soft tissues. A solitary fibrous tumor of the CNS, head, neck, and spine can be challenging to diagnose on imaging. Preoperative consideration of a solitary fibrous tumor is critical, especially in the setting of a high-grade solitary fibrous tumor, which has a high recurrence rate and metastatic potential. This review highlights multimodal imaging features of solitary fibrous tumors, including CT, MR imaging (SWI, MRA, MRS, DWI, and perfusion), FDG PET, and catheter-directed angiography. Radiologic pathologic correlations are also provided. The management of solitary fibrous tumor is a team effort orchestrated with surgery, radiation oncology, and neurointerventional and diagnostic radiology. For high-grade solitary fibrous tumors, preoperative tumor embolization followed by surgical resection and adjuvant radiation therapy improves patient outcomes. Additional whole-body staging and follow-up MR imaging are important to evaluate recurrence or distal metastasis.Learning Objective: To recognize the multimodal imaging appearance of solitary fibrous tumor in the CNS, head and neck, and spine

Pathological Spectrum of Solitary Fibrous Tumours: A Study of 25 Cases Diagnosed at a Tertiary Care Institute

ABSTRACT
 Objective: To evaluate the clinicopathological and immunohistochemical features of Solitary Fibrous Tumor (SFT) in our hospital.
 Materials and Methods: This is a retrospective descriptive study. All cases of solitary fibrous tumor diagnosed on morphology from January 2012 till June 2018 were retrospectively retrieved from the histopathology department of a tertiary care hospital. The hematoxylin and eosin (H&E) stained slides as well as IHC slides were reviewed. Diagnosis was established on current standard histopathological and IHC criteria provided by World Health Organization (WHO) Classification of soft tissue tumors.8
 Four micron thick sections from paraffin blocks were made of each sample and mounted onto glass slides. IHC staining for anti-STAT6 antibody (BioSB antibody, Roche kit) was available in our hospital from 2018 onwards. It was performed on all suspected cases of SFT using manufacturer’s instructions. The quality of expression was graded and interpreted as absent staining, weak expression or strong expression. The samples were graded based on diffuse (>50%) versus localized (<50% of tumor cells) staining, as well as localization of the stain within the cell (nuclear only, cytoplasmic only or both nuclear and cytoplasmic).
 Approval for acquisition of the tissue specimens and supporting case information and retrieval of glass slides was obtained by Institutional Review Board & Ethics Committee.
 Results: There were 25 cases of SFT in our study involving 12 males and 13 females. According to WHO 2013 criteria, eleven cases in our study were classified as malignant (44%) while 14 cases were in the benign group (56%). STAT6 was available in our hospital in 2018 and since then all the subsequent cases of SFT in the present study (seven in number) came positive for STAT6 (sensitivity 100%) while CD34 which was done throughout the duration of this study (January 2012-June 2018) was positive in 20 cases (86.9%) and negative in three cases (13%). Follow-up of 16 cases is available. Out of a total 14 benign cases, follow-up of only seven (50%) cases could be traced and from a total of 11 malignant cases, follow-up of nine (81%) cases could be sought. All benign cases remained disease free while among the nine malignant cases: three (33.3%) patients died, recurrence was reported in four (44.4%) patients. One (11.1%) patient remained disease free while one (11.1%) patient is alive and on treatment.
 Conclusion
 Malignancy in SFT is common and must be evaluated meticulously. STAT6 is a highly sensitive marker for the diagnosis of SFTs. Immunohistochemical panel including STAT6, CD34, CD99 and bcl-2 support morphology. Malignant behavior is common and is evaluated by meticulous analysis of gross/microscopic features and close follow-up of the patient. However further advances in the genetics and new tumor markers is in progress and must be followed for definitive decision of tumor behavior and its subsequent treatment.
 Keywords: solitary fibrous tumor, STAT6, CD34

Solitary fibrous tumor: features of the clinical course, radiation and laboratory diagnostics, therapy: A review

Solitary fibrous tumor (SFT) is a relatively rare mesenchymal neoplasm, mainly affecting serous membranes and soft tissues.It is distinguished by a long-term course, a variable risk of metastasis, the possibility of occurrence in any anatomical region, as well as a low-specific histological structure.Moreover, the last two features of SFT are the main causes of diagnostic errors in morphological verification of a neoplasm. Despite the fact that in the twentieth century SFT was mentioned in the scientific literature quite rarely and, as a rule, in the form of single observations, in the last two decades, due to the widespread use of new molecular genetic research methods and the identification of specific mutations in mesenchymal tumors, the quality and accuracy have significantly increased. making a diagnosis. In addition, the clinical observations accumulated in recent decades in a considerable number of cases made it possible to assess in more detail the clinical and morphological parameters of the SFT associated with the risk of local recurrence and the appearance of distant metastases. This article analyzes the modern literature on epidemiology, molecular pathology, features of radiation and morphological diagnostics, aspects of the genesis of solitary fibrous tumor, as well as the choice of optimal treatment for patients.

Soft tissue solitary fibrous tumors of the musculoskeletal system: spectrum of MRI appearances and characteristic imaging features.

Solitary fibrous tumors (SFTs) uncommonly occur in the musculoskeletal system, with limited available data on their MRI appearance. This study was performed to assess the MRI features of SFTs in the musculoskeletal system (MSK-SFTs). Pre-treatment MRI in 39 patients with pathologically proven SFTs in the trunk or extremities was evaluated. Patient demographics, clinical management and follow-up, and lesion histology were reviewed. MRI features including lesion location, size, morphology, signal characteristics, vascularity, and relationship to major neurovascular structures were assessed. MSK-SFTs most frequently occurred in the lower extremity (23/39 cases, 59%), deep to fascia (29/39, 74%), and intermuscular (22/29, 76%) in location. The majority of deep lesions were located along a major neurovascular bundle (20/29, 69%). Lesions had well-defined margins (39/39, 100%), multilobulated contours (27/39, 69%), and measured mean 6.9 ± 2.8cm. The majority of lesions had slightly hyperintense T1 signal (34/39, 87%) and heterogenous intermediate-to-high T2/STIR signal (28/38, 74%). A "pseudo-cerebriform" internal architectural pattern on fluid-sensitive sequences, with internal lobulations and low signal bands/septations, was observed in 63% (24/38) of lesions. Lesions commonly demonstrated prominent intra-lesional (30/39, 75%) and peripheral juxta-lesional flow voids. Local invasion of surrounding structures was uncommon (3/39, 8%). Mitotically active lesions (p = 0.02) and lesions with tumor necrosis (p < 0.01) were larger in size. Tumor necrosis was associated with T1 heterogeneity (p = 0.04). Distant metastasis occurred in 10% (4/39) of patients, all in mitotically active lesions pre-operatively considered at least at intermediate risk of metastasis. MSK-SFTs commonly present as well-defined, hypervascular masses deep to fascia along major neurovascular bundles, with heterogeneous slightly hyperintense T1 signal, intermediate-to-high T2/STIR signal, and prominent macroscopic flow voids.

A case of a large solitary fibrous tumor in the thigh, displaying NAB2ex4-STAT6ex2 gene fusion

A solitary fibrous tumor (SFT) is documented in several body sites. However, there are few reports on the radiological and corresponding histopathological, including immunohistochemical, features of SFT in the lower extremities. A 58-year-old male presented with a lump in his right thigh of 6months duration. Plain radiograph revealed a soft tissue lesion in his right thigh, involving the adjacent mid-diaphysis and showing focal cortical thickening and calcification. Magnetic resonance imaging scans displayed two well-defined, T1-isointense and T2 heterogeneously hyperintense lesions, measuring together 15cm in the intermuscular plane and the juxtacortical location along the mid-diaphyseal region of the right femur. Radiologically, the differential diagnoses considered were undifferentiated pleomorphic sarcoma and synovial sarcoma. Microscopic examination of the core biopsy and the resected tumor revealed a tumor composed of cells with oval to spindle-shaped nuclei in a variably collagenized stroma, including hyalinized blood vessels and focal dystrophic calcification. Mitotic figures were 4/10 high power fields. Immunohistochemically, the tumor cells were positive for CD34, BCL2, and STAT6. Diagnosis of malignant SFT was offered. The tumor displayed NAB2ex4-STAT6ex2 gene fusion on molecular testing. This constitutes a relatively uncommon case report of a large SFT in the thigh, including its radiological and pathological features, confirmed by STAT6 immunostaining. An SFT should be considered in cases of slow-growing, well-defined soft tissue tumors, which are isointense on T1 and heterogeneously hyperintense on T2-weighted sequences, and display calcification and cortical thickening of the adjacent bones. Various differential diagnoses and their treatment-related implications in such cases are discussed herewith.

Clinical, Histological, and Molecular Features of Solitary Fibrous Tumor of Bone: A Single Institution Retrospective Review.

Simple SummarySolitary fibrous tumors arising from the bone are an extremely rare event and only few cases have been previously described in the literature. It is characterized by a prominent, branched vascularization, with a thin and dilated vascular texture defined as “staghorn” and by the presence of the NAB2-STAT6 gene rearrangement, present in about 90% of cases and considered a pathognomonic feature. In the present study, we described our series of 24 cases of primary solitary fibrous tumor of the bone to find any clinical and molecular prognostic factors and to compare them with those currently used for soft tissue solitary fibrous tumor and to evaluate the risk stratification system proposed by Demicco, in order to understand whether this system was able to correctly predict the risk of local and distant metastatic relapse even in the case of solitary fibrous tumor of the bone.Primary solitary fibrous tumor (SFT) of the bone is extremely rare, with only few cases reported in the literature. We retrieved all cases of primary SFT of the bone treated at our institution and we assessed the morphology and the immunohistochemical and molecular features to investigate the clinical outcome of primary SFT of the bone and any clinical relevance of clinical and histological criteria of aggressiveness currently adopted for the soft tissues counterpart. Morphologically, 15 cases evidenced high cellularity, cytologic atypia, and foci of necrosis and were associated with more than 4 mitotic figures/10 HPF. Immunohistochemical analysis showed an expression of CD34 and of STAT6 immunopositivity in 95% and in 100% of cases, respectively. The presence of NAB2-STAT6 chimeric transcripts was found in 10 out of 12 cases in which RT-PCR analysis was feasible, whereas TERT promoter mutations analysis was feasible in 16 cases and only a C-to-T substitution in a heterozygous state was found in one DNA sample for the C228T genetic variant. P53 variants were assessed in 12 cases: 11 (91.6%) cases showed a variation, while in one case, no alteration was found. Disease-specific survival was 64% at 5 years and 49% at 10 years. Statistical analysis showed no correlation between survival and all the clinicopathological and molecular parameters evaluated. In conclusion, at difference to SFT of soft tissues, aggressive behavior of primary SFT of the bone seems to be independent from mitotic count or any other clinicopathological and molecular features.

Orbit Solitary Fibrous Tumor: A Proposed Risk Prediction Model Based on a Case Series and Comprehensive Literature Review.

Solitary fibrous tumors (SFTs) of the orbit are rare. In order to further characterize the clinical and pathologic features of solitary fibrous tumor arising at this anatomic site, 12 cases of orbital SFTs were analyzed in conjunction with a review of 263 cases reported from the English literature in order to develop a risk prediction model. SFTs of the orbit were equally distributed between males (n = 5) and females (n = 7) with a mean patient age of 46.8years (median 44.5years; range 18-76years) at initial diagnosis. The patients typically presented with swelling or mass around the orbit, with proptosis (n = 10), ptosis (n = 5), and visual changes (n = 6). Tumors were orbital (n = 10) or upper eyelid (n = 2). Mean tumor size was 2.5cm (median 2.6cm). Microscopically, the tumors were characterized by cytologically bland spindle cells with patternless growth, hypocellular and hypercellular areas, variable amounts of collagen, and ectatic, branching blood vessels. By immunohistochemistry, all cases had a strong nuclear STAT6 expression. All patients were initially managed with excision or biopsy, three with presurgical embolization. The two patients with biopsy only had persistent disease (mean 37.2months), but a third patient developed distant bone metastasis at 86.9months. Overall mean follow-up was 73.1months: 9 patients are alive or dead without disease (mean 77.9months), two patients with persistent disease,and one patient with metastatic disease at last follow-up (102months). Incorporating cases sufficiently reported in the literature, a risk prediction model based on age > 45years, tumor size > 3cm, tumor necrosis, mitoses of > 4/2 mm2, moderate to high cellularity, and moderate to severe pleomorphism allows for risk stratification for the development of local recurrence and distant metastasis. In conclusion, orbital SFTs are rare, but can be reliably diagnosed based on the presence of characteristic morphologic features and STAT6 immunohistochemistry. Orbital tumors tend to show a higher frequency of local recurrence than distant metastasis, which can be predicted by a risk stratification model unique to orbital tumors. With late disease common, long term clinical follow-up is recommended.

Radiologic and Pathologic Findings of a Huge Solitary Fibrous Tumor of the Liver with Malignant Transformation: A Case Report

: Solitary fibrous tumors (SFTs) are mesenchymal tumors that mostly occur in the pleural cavity. Extra-thoracic location is rare and hepatic origin is extremely rare. Most lesions are benign, 10% - 15% show aggressive behavior and few metastasizing SFTs have been reported. Imaging features of solitary fibrous tumors of the liver (SFTLs) are nonspecific and definite diagnosis usually needs histopathological and immunohistochemistry evaluation. We report ultrasound, CT and MRI features of such a rare malignant SFTL in a 47-year-old man who came with vague abdominal symptoms in detail along with reviewing literature considering imaging features which is valuable for radiologists. The lesion seen as a huge dominantly cystic lesion on ultrasound was initially misinterpreted as hydatid. On CT scan it was seen as a large encapsulated mass with arterial hyper-enhancement and delayed contrast retention and multiple cystic spaces. On MRI, solid components showed iso-intensity to adjacent liver on T1 and T2 images, small areas of restriction on diffusion weighted imaging (DWI) and few hemorrhagic cystic components beside enhancement pattern and multiple large cystic components similar to CT scan. Our patient was admitted for resection of huge hepatic mass and experienced an episode of altered mental status due to hypoglycemia during hospital admission, which is a rare finding in SFTL. The patient underwent right hepatectomy and solitary fibrous tumor was confirmed on pathologic examination of the resected tumor. Hypoglycemic episodes were resolved and the patient was asymptomatic in 28 months follow-up.

Histological and molecular features of solitary fibrous tumor of the extremities: clinical correlation.

Solitary fibrous tumor is a rare mesenchymal neoplasm that exhibits a broad spectrum of biological behaviors. Few studies relative to clinical-pathologic features and predictive factors have been reported, all involving a mixed population of tumors occurring at different anatomic sites. In this study, we described a cohort of 41 patients with solitary fibrous tumor of the extremities and evaluated the prognostic role of clinical and histological features, presence of C228T and C250T mutations at the TERT promoter region, and NAB2-STAT6 fusion variants. Patients were stratified according to the latest risk stratification model proposed by Demicco. The two patients with metastasis at presentation were in the high-risk group; the one with metastasis after surgery was classified in the intermediate-risk group. TERT promoter mutations were detected in 9 out of 38 DNA available. All patients with metastasis were characterized by a TERT promoter mutation. TERT promoter mutation was associated with mitoses > 4 per high-power field (p = 0.001), necrosis (p = 0.049), and size > 10cm (p = 0.031). NAB2-STAT6 fusion variants were detected in 27 out of 41 cases without any prognostic value. In conclusion, we confirmed that the patients with solitary fibrous tumor of the limbs have a better prognosis than other solitary fibrous tumors, with a very low percentage of metastatic events. Besides, our data support an association between TERT promoter mutations and histologically malignant features, suggesting a possible molecular role in stratifying patients into intermediate- to high-risk tumor.

CT and MRI Features of Solitary Fibrous Tumor of the Liver: A Case Report

CT and MRI Features of Solitary Fibrous Tumor of the Liver: A Case Report

Utility of STAT6 and 13q14 deletion in the classification of the benign spindle cell stromal tumors of the breast

The boundaries of the benign spindle cell stromal tumors of the breast are still confusing. This is the reason why different names are interchangeably used for the same tumor and vice versa the same name for different tumors. Therefore, we studied the immunoexpression of easily available markers, such as CD34, α-smooth muscle actin, and desmin, with the addition of STAT6, as well as the chromosome 13q14 region by fluorescence in situ hybridization analysis in a series of 19 cases of benign spindle cell stromal tumors of the breast. Based on the morphologic and immunohistochemical findings, the following histotypes were identified: (i) tumors (10/19 cases) with the characteristic morphology of myofibroblastoma and stained with vimentin, CD34, desmin, and α-smooth muscle actin; (ii) fibroblastic benign spindle cell tumors (5/19 cases) composed of fibroblast-like cells stained only with vimentin and CD34; (iii) tumors (2/19 cases) with the typical morphologic features of solitary fibrous tumor and stained with vimentin, CD34, and STAT6; (iv) 1 case of spindle cell lipoma stained with vimentin and CD34; and (v) 1 case of fibroma composed of a paucicellular, diffusely hyalinized stroma with expression of vimentin and CD34. Notably most of the tumors, with the exception of solitary fibrous tumor, showed monoallelic deletion of FOXO1. This finding supports that myofibroblastoma, fibroblastic benign spindle cell tumor, spindle cell lipoma, and fibroma of the breast are histogenetically related lesions which belong to the same tumor entity.

Clinical analysis of CT and MRI Features of Solitary Fibrous Tumour of the Soft Tissues

Objective: The aim of this study was to report and analyze outcomes associated twenty-eight patients’ in-hospital evaluation of the computed tomography (CT) and magnetic resonance imaging (MRI) features of solitary fibrous tumors (SFTs) in various anatomic regions.Methods: A number of twenty-eight patients whose clinical data, imaging finding, pathological and immune histochemical findings and with proven SFTs were retrospectively reviewed of the first affiliated hospital of Anhui medical university of January 2012 to 2015 were identified and included for analysis. Twenty-one patients (17 with contrast) had undergone CT scan while 7 (4 with contrast) had undergone MRI. Image characteristics and pattern of enhancement on CT and MRI were analyzed and compared with histopathological findings and multivariate analysis.Results: Among 28 patients, 12 SFTs occurred in the thoracic cavity, 4 in the mediastinum, 3 in the retroperitoneum, 2 in the meanings while a single SFT was found in other 7 organs. They appeared as a solitary mass with an oval or irregular shape, well-defined or ill-defined margin. The size ranged from 1.5 ×1.0 cm2 to 23.0 × 16.5 cm2. Plain CT revealed homogeneous iso-density in 10 and heterogeneous iso-density in 11 cases. Out of the 17 contrast enhanced cases, 11 cases showed slight enhancement and 6 showed marked heterogeneous enhancements during the arterial phase (AP). Progressive and prolonged enhancement was observed in the dynamic contrasted scan. Most of tumors (14/17) exhibited serpentine vessel sign in AP. Hypo- or iso-intensity on T1WI and hyper-or isointensity onT2WI were revealed on MRI. Six cases (6/7) showed the flow voids sign on T2WI.Conclusion: SFTs typically present as large, well-defined, heterogeneous, progressively enhancing mass in pleural and extra-pleural regions. The valuable diagnostic features are serpentine vessels in arterial phase (CT) and flow voids sign on T2WI (MRI).

Malignant Giant Solitary Fibrous Tumor of the Pleura Metastatic to the Thyroid Gland

Solitary fibrous tumor (SFT) of the pleura is a rare mesenchymal neoplasm arising from mesenchymal cells in the areolar tissue subjacent to the mesothelial-lined pleura and accounting for less than 5% of primary pleural tumors. SFTs are generally benign and asymptomatic, with 10-year survival rates of up to 98%. Unfortunately, approximately 10% have malignant potential, leading to local recurrence after radical surgery and/or metastatic spread. Of note, giant pleural SFT, which consists of a tumor occupying at least 40% of the affected hemithorax, is even less common with only anecdotal cases reported in the medical literature. We describe a unique case of giant SFT of the pleura that metastasized to the thyroid gland 1 year after complete resection, focusing on its clinical and pathological features of presentation. En bloc resection remains the mainstay of therapy with curative intent. Patients with large tumors may undergo preoperative angiography with percutaneous embolization of the tumor, which allows to reduce perioperative bleeding. In case of local recurrence, surgery still remains the best treatment option. However, surgery can also be considered in patients with isolated metastatic spread. Every suspected and proven SFT of the pleura should undergo surgical resection, as clinical and radiological criteria cannot accurately distinguish benign from malignant forms. Moreover, the peculiar histological features of SFT should not be neglected when planning clinicoradiological follow-up. Additionally, suspicious clinical findings during follow-up should always be thoroughly investigated in order to exclude or confirm the diagnosis of recurrent disease.

Metastatic Patterns of Solitary Fibrous Tumors: A Single-Institution Experience.

The objective of our study was to evaluate the metastatic patterns and imaging features of solitary fibrous tumors (SFTs). This retrospective study included 139 patients with pathologically proven SFT, 49 of whom developed metastases. Electronic medical records and all available images were reviewed to record the pattern and imaging appearances of metastatic disease, and comparisons of thoracic SFTs and extrathoracic SFTs were also performed. Associations of metastatic spread were studied using univariate and multivariate Cox regression analyses. A total of 49 (35%) patients developed metastases at a median of 124 months (interquartile range [IQR], 66-195 months) after SFT diagnosis; 11 patients (8%) had metastases at presentation. Of these 49 patients, 40 patients died at a mean of 183 months after diagnosis. The associations with metastatic disease on univariate analysis were tumor size ≥ 10 cm (p = 0.01) and malignant pathology or mitotic count ≥ 4 per 10 high-power fields (HPF) (p < 0.001). Malignant pathology and a mitotic count of ≥ 4 per 10 HPF were also associated with metastatic disease on multivariate analysis (p = 0.01; hazard ratio, 0.22; 95% CI, 0.05-0.73). The most common sites of metastasis were the lungs (30/49, 61%) followed by the pleura (24/49, 49%) and then the liver (20/49, 41%), bones (20/49, 41%), and peritoneum (20/49, 41%). A significantly higher proportion of patients with extrathoracic SFT had metastatic disease (37/139, 27%) compared with those with thoracic SFT (12/139, 9%) (p = 0.003). The overall metastasis-free survival was a median of 117 months (IQR, 33-169 months) in patients with extrathoracic SFT and a median of 120 months (IQR, 82-169 months) in patients with thoracic SFT (p = 0.01). A mitotic count of ≥ 4 per 10 HPF or malignant pathology was significantly associated with metastatic disease on both univariate and multivariate analyses. The sites of metastatic disease differed depending on the site of the primary SFT but were most commonly the lung and pleura. Patients with extrathoracic SFT were statistically more likely to develop metastatic disease than those with thoracic SFT.

Clinicopathologic features of solitary fibrous tumor in urogenital system

To study the clinicopathologic features and differential diagnosis of solitary fibrous tumor (SFT) in the urogenital system. The clinical data and pathologic characteristics of eight cases of SFT in the urogenital system were analyzed, and the relevant literature was reviewed. The cohort included six male and two female patients, with age of onset ranging from 25 to 80 years. Five occurred in the kidney (three in the right kidney), one case each occurred in the bladder, the prostate and the spermatic cord. Most patients showed no obvious clinical symptoms or only had low back pain and swelling. The diameter of the tumor was ranged from 2.5 to 11.8 cm (median 5.2 cm). Microscopy showed at low magnification, the tumor cells were spindle-shaped and arranged in bundles or helicoid pattern. The regional mesenchymal fibroblasts showed hyperplasia, with obvious collagenization and formed hemangiopericytoma-like structure. One case showed increased mitotic figures (>5 cells/10 HPF) and focal necrosis. By immunohistochemistry, the tumor cells were positive for CD34 and STAT6 in all eight cases, CD99 and vimentin in six cases, bcl-2 in four cases and SMA in one case. All seven cases with follow-up did not show any tumor recurrence or metastasis. SFT is rare in the urogenital system and most patients show good prognosis. SFT expresses CD34 and STAT6 and needs to be distinguished from other spindle cell tumors.

Different clinical and radiological features of solitary fibrous tumor of the pleura: Report of two cases

We report two cases of solitary fibrous tumor of the pleura (SFTP). The first appeared in a young, new mother as a large mass in the upper lobe of the left lung that caused compression of lung parenchyma without significant respiratory symptoms but with polyarticular paraneoplastic syndrome; the other was documented by an occasional chest x-ray in a man affected by chronic obstructive pulmonary disease (COPD) as a small peripheral mass 4 years before and no longer controlled. Both patients underwent surgical resection with quick and full recovery. SFTP is a benign, slow growing neoplasm that is mostly localized. It appears in adult or elderly patients often with few symptoms. The computed tomography (CT) of the chest with contrast medium is important in order to see the shape of the mass and relationships with adjacent structures but only histology can provide the diagnosis. Surgery is the best treatment.

Tumor fibroso solitario de la mama: presentación de caso y revisión de la literatura

Solitary fibrous tumor, previously called hemangiopericytoma, is a benign mesenchymal tumor composed of ovoid spindle cells within collagen fibers. Its presentation in the breast is rare, with around 50 cases reported in the medical literature. We present the case of a 36-year-old woman with a right breast mass with phenotypic and immunohistochemical features of solitary fibrous tumor. In addition, we provide a review of published cases in the literature.

Enhanced CT and FDG PET/CT in Malignant Solitary Fibrous Tumor of the Lung

Although some histological features of solitary fibrous tumor are related to its aggressive behavior, tumors with benign features may also follow an aggressive behavior. An 18-year-old male patient was referred after the detection of multiple bilateral pulmonary lesions on a chest x-ray in a health examination 2 months ago. These lesions showed inhomogeneous enhancement on enhanced CT and intense FDG uptake (SUVmax, 21.8) on PET/CT. CT-guided biopsy revealed histologically benign solitary fibrous tumor.

Metastatic melanoma mimicking solitary fibrous tumor: report of two cases

Malignant melanomas are known for their remarkable morphological variation and aberrant immunophenotype with loss of lineage-specific markers, especially in recurrences and metastases. Hot spot mutations in BRAF, NRAS, GNAQ, and GNA11 and mutations in KIT are oncogenic events in melanomas. Therefore, genotyping can be a useful ancillary diagnostic tool. We present one case each of recurrent and metastatic melanoma, both showing histological and immunohistochemical features of solitary fibrous tumor (SFT). Mutational analysis detected BRAF and NRAS mutations in the primary and secondary lesions, respectively. This result confirmed the diagnosis of recurrent/metastastic melanoma.