Rare presentation of solitary fibrous tumour in the floor of the mouth

A male in his 20s, a tobacco chewer, presented to the outpatient department with a history of painless, slowly progressive swelling in the floor of the mouth. After a thorough history and clinical examination, MRI was done and the tumour was completely excised. Histopathological examination revealed the mass to be a solitary fibrous tumour, confirmed with immunohistochemical markers. On subsequent follow-ups, the patient was found to be asymptomatic with no clinical signs of recurrence.

CD34-Positive Spindle Cell Tumor With CTNNB1 Mutation: An Unusual Spindle Cell Variant of Sinonasal Glomangiopericytoma

Sinonasal glomangiopericytoma is an uncommon mesenchymal tumor with a perivascular myoid phenotype, which is categorized as a borderline/low-grade malignant soft tissue tumor by the current World Health Organization Classification of Head and Neck tumors. Here, we present the case of a 53-year-old woman with an unusual spindle cell morphology of sinonasal glomangiopericytoma arising in the nasal cavity, mimicking solitary fibrous tumor. Microscopically, the tumor showed a cellular proliferation of spindle cells in fascicles including a focal long sweeping arrangement or whorls, or with a storiform growth pattern, associated with hemangiopericytoma-like gaping blood vessels embedded in a fibrous stroma. This arrangement of the spindle cells faintly indicated a solitary fibrous tumor rather than sinonasal glomangiopericytoma. Immunohistochemically, the tumor was positively reactive to not only beta-catenin (in the nuclei) but also CD34, although signal transducers and activators of transcription 6 was negative. Mutational analysis using Sanger sequencing detected a CTNNB1 mutation. We finally diagnosed the tumor as a sinonasal glomangiopericytoma, showing an unusual spindle cell variant. Such unusual spindle cell morphology with CD34-immunoreactivity potentially leads to an incorrect diagnosis of solitary fibrous tumor because such prominent fascicles including long sweeping structures, reminiscent of desmoid-type fibromatosis, have scarcely been described in the literature. Hence, careful morphological scrutiny using appropriate diagnostic adjuncts is necessary for correct diagnosis.

Endobronchial solitary fibrous tumors: An enigma for diagnosis

Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms constituting less than 2% of all soft tissue tumors. They typically originate in the thoracic cavity, mainly in the pleura, but can also occur in other various sites such as lung parenchyma, pericardium, and bronchus. In this study, a 49-year-old non-smoking female with a history of allergies presented to our pulmonary clinic with a chronic cough. An explorative bronchoscopy revealed an intrabronchial mass in the left superior bronchi, and a 68 Ga-DOTATOC positron emission computed tomography suggested a carcinoid tumor. Subsequent pulmonary segmentectomy unveiled a well-circumscribed polypoid lesion diagnosed as a low-grade bronchus SFT through histopathological and immunohistochemical assessments. The patient was asymptomatic after surgical excision and showed no other lesion during the 6-month follow-up. The endobronchial location of SFT is uncommon, with only a few reported cases in the literature, underscoring the necessity of considering various differential diagnoses, including carcinoid, mucoepidermoid carcinoma, endobronchial pleomorphic adenoma, hamartoma, leiomyoma, and metastasis, depending on location and imaging features. This report underscores the importance of careful histological and immunohistochemical evaluation in understanding and appropriately stratifying the risk associated with polypoid lesions.

Solitary fibrous tumours involving the genitourinary tract: a case series in rare locations, highlighting the role of STAT6 immunohistochemistry

Solitary fibrous tumour (SFT) is a mesenchymal neoplasm with variable behaviour, very rarely involving the genitourinary (GU) tract. Most reported cases correspond to isolated case reports. STAT6 immunohistochemistry is a more recent and reliable diagnostic marker. The pathology database of two tertiary institutes was searched for SFTs involving the GU tract. STAT6 strong diffuse nuclear staining confirmed the diagnosis in all four cases, and the NAB2::STAT6 fusion was demonstrated by NGS in one case. Two cases were diagnosed in needle biopsy, one involving the prostate and the other involving the seminal vesicle. One case corresponded to a pelvic mass inseparable from and infiltrating the prostate and bladder. The remainder represented an exceedingly rare involvement of the spermatic cord. Involvement by a SFT should be considered in the differential diagnosis of spindle cell lesions involving GU organs. STAT6 strong diffuse nuclear staining is an important ancillary tool, particularly in a biopsy.

A case report on a nasal and oral cavity involving large solitary fibrous tumor and comprehensive review of case literature

Solitary fibrous tumor (SFT) represents an uncommon spindle cell sarcoma predominantly situated within soft tissue, with a notably infrequent occurrence in the nasal cavity and paranasal sinuses. In this report, we present a case involving a middle-aged male with a sizable solitary fibrous tumor affecting both the nasal and oral cavities.

Conditional survival analysis and dynamic survival prediction for intracranial solitary-fibrous tumor/hemangiopericytoma

BACKGROUND

As the form of World Health Organization Central Nervous System (WHO CNS) tumor classifications is updated, there is a lack of research on outcomes for intracranial combined solitary-fibrous tumor and hemangiopericytoma (SFT/HPC). This study aimed to explore conditional survival (CS) pattern and develop a survival prediction tool for intracranial SFT/HPC patients.

METHODS

Data of intracranial SFT/HPC patients was gathered from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute. The patients were split into training and validation groups at a 7:3 ratio for our analysis. CS is defined as the likelihood of surviving for a specified period of time (y years), given that the patient has survived x years after initial diagnosis. Then, we used this definition of CS to analyze the intracranial SFT/HPC patients. The least absolute shrinkage and selection operator (LASSO) regression and best subset regression (BSR) were employed to identify predictive factors. The Multivariate Cox regression analysis was applied to establish a novel CS-based nomogram, and a risk stratification system was developed using this model.

RESULTS

From the SEER database, 401 patients who were diagnosed with intracranial SFT/HPC between 2000 and 2019 were identified. Among them, 280 were included in the training group and 121 were included in the internal validation group for analysis. Our study revealed that in intracranial SFT/HPC, 5-year survival rates saw significant improvement ranging from 78% at initial diagnosis to rates of 83%, 87%, 90%, and 95% with each successive year after surviving for 1-4 years. The LASSO regression and BSR identified patient age, tumor behavior, surgery and radiotherapy as predictors of CS-based nomogram development. A risk stratification system was also successfully constructed to facilitate the identification of high-risk patients.

CONCLUSION

The CS pattern of intracranial SFT/HPC patients was outlined, revealing a notable improvement in 5-year survival rates after an added period of survival. Our newly-established CS-based nomogram and risk stratification system can provide a real-time dynamic survival estimation and facilitate the identification of high-risk patients, allowing clinicians to better guide treatment decision for these patients.

A case of fat-forming solitary fibrous tumor that is prone to be confused with liposarcoma

Fat-forming solitary fibrous tumor is a rare and specific subtype of solitary fibrous tumor. In this case, a mass of 8.3 cm in diameter was found in a 59-year-old male patient's right retroperitoneum, as revealed by abdominal contrast-enhanced computed tomography (CT) images. The tumor exhibited a well-circumscribed nature and histological features characterized by a combination of hemangiopericytomatous vasculature and mature adipose tissue, comprising around 70% of the total tumor composition. Immunohistochemistry staining revealed diffuse positive expression of STAT6 and CD34 in the tumor cells. Based on these findings, the final diagnosis was determined to be a fat-forming solitary fibrous tumor located in the retroperitoneum. It is important to consider other potential differential diagnoses, including angiomyolipoma, dedifferentiated liposarcoma, spindle cell lipoma, and atypical lipomatous tumor/well-differentiated liposarcoma.

Solitary fibrous tumor: Can the new Huang risk stratification system for orbital tumors improve prognostic accuracy in other tumor locations?

Solitary fibrous tumors (SFTs) are known for their heterogeneous morphology, characterized by a variety of cell shapes and different growth patterns. They can also arise in various anatomical locations, most commonly in extremities and deep soft tissues. Despite this diversity in morphology and location, all SFTs share a common molecular signature involving the NAB2::STAT6 gene fusion. Due to their unpredictable clinical behavior, establishing prognostic factors is crucial. This study aims to evaluate an orbital risk stratification system (RSS) proposed by Huang et al. for use in extraorbital SFTs using a database of 97 cases. The Huang model takes into consideration tumor size, mitotic figures, Ki-67 index, and dominant constituent cell (DCC) as key variables. Survival analysis confirmed the model's predictive value, with higher-risk scores being associated with poorer outcomes. However, in contrast to the orbital SFTs studied by Huang et al., our study did not find a correlation between tumor size and recurrence in extraorbital cases. While the Huang model performs slightly better than other RSS, it falls short on achieving statistical significance in distinguishing recurrence risk groups in extraorbital locations. In conclusion, this study validates the Huang RSS for use in extraorbital SFTs and underscores the importance of considering DCC, mitotic count, and Ki-67 together. However, we found that including tumor size in this model did not improve prognostic significance in extraorbital SFTs. Despite the benefits of this additional RSS, vigilant monitoring remains essential, even in cases classified as low-risk due to the inherent unpredictability of SFT clinical outcomes.

Solitary Fibrous Tumours of the Orbit - Clinical Pathology, Therapy and Prognosis

BACKGROUND

Solitary fibrous tumours are rare. The aim of this study is to describe the clinical features, therapy and outcome of affected patients and to identify factors associated with recurrence.

METHODS

Retrospective study of a cohort of 20 patients who underwent surgery for orbital solitary fibrous tumour at the University Department of Oral and Maxillofacial Surgery between 2002 and 2023. Demographic, clinical, and therapeutic data as well as tumour follow-up results were collected. Tumour volume and molecular genetic mutations were retrospectively determined.

RESULTS

The median patient age was 49.5 years at initial surgery. The left orbit was affected in 65% of cases. The most common clinical symptom was proptosis (80%). This was reported with a mean lateral difference of 3.9 mm (range: 1 - 10 mm). The tumours were localised predominantly in the intra- and extraconal space, craniolateral quadrant and middle third. The median tumour volume was 7.66 cm³ (range 2.15 - 12.57 cm³). In all patients, the diagnosis was made by pathological examination. All tumours investigated showed a NAB2-STAT6 mutation. The most frequently detected mutation was the fusion NAB2 exon 4 - STAT6 exon 2. All patients were initially managed with frontolateral orbitotomy. Incomplete resection (R1-status) occurred in 35% (n = 7). The recurrence rate was 25% (n = 5), with a median disease-free interval of 45.5 months (range 23 - 130). 80% (n = 4) of recurrences were initially R1-resected.

CONCLUSION

Orbital solitary fibrous tumours are rare tumours and are clinically manifested by signs of displacement of orbital structures. Diagnosis is made by histology and immunohistochemistry and can be proven with the molecular genetic detection of the NAB2-STAT6 mutation. The therapy of choice is complete surgical resection. R1-resection is more likely in the intraconal location as well as in location in the posterior third of the orbit - due to difficult surgical accessibility. The greatest risk factor for the development of recurrence is incomplete surgical excision. Late recurrences are possible, which is why a long-term connection to a specialised clinic is necessary.

Establishment and characterization of a patient-derived solitary fibrous tumor/hemangiopericytoma cell line model

Solitary fibrous tumor/Hemangiopericytoma (SFT/HPC) is a rare subtype of soft tissue sarcoma harboring NAB2-STAT6 gene fusions. Mechanistic studies and therapeutic development on SFT/HPC are impeded by scarcity and lack of system models. In this study, we established and characterized a novel SFT/HPC patient-derived cell line (PDC), SFT-S1, and screened for potential drug candidates that could be repurposed for the treatment of SFT/HPC. Immunohistochemistry profiles of the PDC was consistent with the patient's tumor sample (CD99+/CD34+/desmin-). RNA sequencing, followed by Sanger sequencing confirmed the pathognomonic NAB2exon3-STAT6exon18 fusion in both the PDC and the original tumor. Transcriptomic data showed strong enrichment for oncogenic pathways (epithelial-mesenchymal transition, FGF, EGR1 and TGFβ signaling pathways) in the tumor. Whole genome sequencing identified potentially pathogenic somatic variants such as MAGEA10 and ABCA2. Among a panel of 14 targeted agents screened, dasatinib was identified to be the most potent small molecule inhibitor against the PDC (IC50, 473 nM), followed by osimertinib (IC50, 730 nM) and sunitinib (IC50, 1765 nM). Methylation profiling of the tumor suggests that this specific variant of SFT/HPC could lead to genome-wide hypomethylation. In conclusion, we established a novel PDC model of SFT/HPC with comprehensive characterization of its genomic, epigenomic and transcriptomic landscape, which can facilitate future preclinical studies of SFT/HPC, such as in vitro drug screening and in vivo drug testing.

Metastasis of solitary fibrous tumor to the parotid gland diagnosed on aspiration cytology supplemented with immunocytochemistry

Solitary fibrous tumor (SFT) can occur in varied anatomic locations, most commonly being the extremities-superficial and deep soft tissues, followed by retroperitoneum, visceral organs, and the bone. Head and neck region may harbor a few with a predilection for the orbit and sinonasal tract, oral cavity, and rarely the salivary glands. The parotid gland is most involved among all salivary glands. Overall, SFT in salivary glands is rare and mostly seen as a primary tumor. The occurrence of metastasis to the parotid gland is exceedingly uncommon. We present cytological findings of SFT, metastatic to the parotid gland in a young 31-year-old lady where the diagnosis was confirmed with the help of immunocytochemistry (ICC) on the cell block. The smears were highly cellular and showed predominantly discrete round to oval tumor cells with mild pleomorphism, coarse chromatin, inconspicuous nucleoli, and scanty cytoplasm. Mitosis and focal areas of necrosis were noted. Lymphoglandular bodies were absent ruling out a non-Hodgkin lymphoma. Features were of a poorly differentiated malignant tumor with differentials being sarcoma, myoepithelial carcinoma, and carcinoma ex-pleomorphic adenoma. A panel of ICC was done and positivity for signal transducer and activator of transcription 6 (STAT6) helped in clinching the correct diagnosis of SFT.

Solitary fibrous tumor of the tympanic membrane a case report and systematic review

PURPOSE

Otological solitary fibrous tumors (SFT) are exceedingly rare. There has been no report of SFT localized to the tympanic membrane. To report on a rare case of solitary fibrous tumor of the tympanic membrane and provide systematic review of the literature pertaining the demographics and pathophysiology of otological SFTs.

MATERIALS AND METHODS

This review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. A search of PubMed, Google Scholar, and Cochrane Library databases was conducted to identify English-language articles on solitary fibrous tumor of the ear, with emphasis on the tympanic membrane, published through 2022. A combination of Boolean operators and the following keywords were included in the search strategy: "solitary fibrous tumor", "tympanic membrane", and "ear".

RESULTS

We found 12 previous reports of solitary fibrous tumors of the ears, none of which were in the tympanic membrane. All cases underwent surgical resection, with or without perioperative embolization, or radiation. There was no evidence of distant diseases in any cases.

CONCLUSIONS

In the context of a tympanic membrane mass with associated pain and hearing loss, our findings suggest that solitary fibrous tumor should be included in the differential diagnosis.

Presentation of orbital solitary fibrous tumours

AIMS

To evaluate presenting features of patients with orbital solitary fibrous tumours (SFTs), based on histological phenotype.

METHODS

A retrospective case-note review was performed for demographics and presenting features for patients with orbital SFTs. The tumours were classified as "Group IA" hypocellular SFT phenotype, "Group IB" haemangiopericytoma phenotype and low mitotic activity, and high-grade "Group II" haemangiopericytoma phenotype with high mitotic activity.

RESULTS

Sixty-four patients (34 female; 53%) presented at a mean age of 42.2 years (median 38; range 19-82), with Group II patients presenting at an older age (mean 53 years). Median symptom duration was 12 months for Groups IA and IB, compared to 4 months for Group II, the commonest symptoms being proptosis (53%), diplopia (41%), periorbital swelling (31%), and altered vision (19%). Mean LogMAR was 0.17 (median 0.0; range -0.2-4), and 14% had ipsilateral optic neuropathy, with no significant difference between the three groups. Non-axial displacement was noted in 69%, a palpable mass in 45%, and reduced eye movements in 59%; choroidal folds and optic disc swelling were recorded in 12% and 9%. SFTs were mostly extraconal (59%), within the superior and superonasal quadrants (44%), with an average estimated tumour volume of 4.9 ml (median 3.6; range 0.31-14.5 ml).

CONCLUSION

SFTs may present with impaired visual function (∼15%), fundal abnormalities (a fifth), globe displacement (two-thirds), and reduced ocular motility (over a half). High-grade tumours tend to present more than a decade later, with a shorter duration of symptoms.

Extra-meningeal solitary fibrous tumor: an evolving entity with chameleonic morphological diversity, a hallmark molecular alteration and unresolved issues in risk stratification assessment

Solitary fibrous tumor (SFT) is a rare type of mesenchymal lesion with variable clinical presentation in which specific clinicopathologic factors have been related to patient outcome. SFT shares an important morphologic and immunohistochemical overlap with other sarcomas, hence the differential diagnosis is challenging. Although molecular studies provide significant clues, especially in the differential diagnosis with other neoplasms, a thorough hematoxylin and eosin analysis and the integration of phenotypical, clinical, and radiological features remain an essential tool in SFT diagnosis. In this review, we discuss some emerging issues still under debate in SFT.

Malignant recurrent orbital solitary fibrous tumor

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor of fibroblastic origin commonly occurring in pleura. It can occur at many extrapleural sites but is rare in orbit. Most cases are benign and recurrence is not unusual in the head and neck and orbit and is usually due to incomplete surgical excision. However, malignant transformation (MT) in orbital SFT is extremely unusual. We present a case of orbital SFT in adult male who developed recurrence with MT eight years after initial surgical excision. He underwent left orbital exenteration. The recurrent tumor revealed features of malignancy with areas exhibiting morphology typical of SFT. The immunochemistry confirmed the diagnosis of SFT with MT. The patient was given adjuvant radiation and was disease free for the last 18 months. Identification of malignancy in orbital SFT is important for the patient to receive appropriate postoperative treatment, as seen in the present case.

Solitary Fibrous Tumors of the Mesocolon: A Report of Two Cases and Review of Literature

Solitary fibrous tumors (SFTs) are an uncommon group of neoplasms. The visceral pleura is the most common site of origin of these tumors. The colonic mesentery is an unusual site of origin of SFTs. A pre-operative diagnosis of SFT is challenging as there are no pathognomonic clinical or radiological signs. Most patients reported thus far were diagnosed post-operatively with the aid of immunohistochemical markers. Complete surgical excision is the treatment of choice for SFTs. Recurrences are uncommon. However, they can occasionally show aggressive behavior. In this report, we describe two cases of rare colonic mesentery SFTs.

A case report of solitary fibrous tumor of the thyroid gland and literature review

RATIONALE

A solitary fibrous tumor (SFT) is an uncommon soft tissue tumor that was first discovered in the pleura. Although SFTs have been documented in other extra-pleural sites, an SFT in the thyroid gland is highly unusual. An SFT of the thyroid gland can be difficult to diagnose, and there is little information about their Underlying biological behavior.

PATIENT CONCERNS

We present a case of a 63-year-old man with a progressively growing left-neck mass detected 1 month ago, which was pathologically confirmed to be a benign SFT of the thyroid gland.

DIAGNOSIS

Postoperative pathological examination of the tumor revealed an SFT. Immunopathological examination was consistent with the diagnosis of an SFT.

INTERVENTIONS

The patient underwent surgical resection of the SFT.

OUTCOMES

The patient was recurrence-free during 1.5 years of follow-up.

LESSONS

Surgical excision is beneficial in SFTs that show no histological signs of malignancy, such as pleomorphism, enhanced mitotic activity, necrosis, bleeding, or capsular invasion. However, because the biologic activity remains unknown, meticulous long-term monitoring is required.

Giant Solitary Fibrous Tumor of the Ascending Aortic Wall Causing Reversible Heart Failure: A Case Report and Review of the Literature

A 56-year-old woman was admitted to our hospital with a 2-week history of chest tightness and fatigue, and an echocardiogram revealed a massive polyserous cavity effusion. A massive (13.5 cm maximum diameter) intrapericardial mass was discovered using computed tomography (CT) and cardiovascular magnetic resonance imaging (MRI) in the ascending aortic wall. A pericardial biopsy was performed and diagnosed as a solitary fibrous tumor (SFT). After successful mass resection, an immunohistochemical test was positive for CD34, STAT-6, CD34, and Bcl2, which indicates a giant benign solitary fibrous tumor of the ascending aortic wall. After three years of follow-up, the patient is symptom-free, and histological indications of malignancy were absent. A giant benign solitary fibrous tumor is extremely rare in the heart, especially from the ascending aorta wall, and experience with this tumor location is limited, so close follow-up at regular intervals is considered necessary. We present this case, followed by a literature review on SFTs involving the heart and management approaches.

Infantile (congenital) anaplastic intracranial solitary fibrous tumor/hemangiopericytoma-A case report with brief literature review

Solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a rare primary central nervous system (CNS) tumor, included in the World Health Organization (WHO) 2016 classification. Very few cases have been described in the literature so far, especially the infantile type. It is a mesenchymal tumor of the fibroblastic type, characterized by the fusion of NAB 2 and STAT 6 genes. A 10-month-old boy presented to our neurosurgery department with complaints of increasing head circumference since 1 month of age. The magnetic resonance imaging (MRI) showed a space-occupying lesion measuring 8.2 cm × 7 cm × 6.9 cm in the fronto-temporo-parietal region with a clinical diagnosis of glioma/atypical teratoid rhabdoid tumor (ATRT). The microscopy revealed a spindle cell tumor arranged in a patternless pattern with variable cellularity, increased mitosis, and areas of coagulative necrosis. The immunohistochemistry showed vimentin, CD 34, STAT6, CD99 positivity whereas Glial fibrillary acidic protein, Epithelial membrane antigen, and S-100 negativity. Hence, a diagnosis of anaplastic SFT/HPC (grade-III) was rendered. The patient improved after gross total resection (GTR). The primary intracranial congenital SFT/HPC are extremely rare, often a clinico-radiologically misdiagnosed entity. Thus, the immunohistochemistry/molecular study in addition to histology is mandatory for accurate diagnosis.

A review of solitary fibrous tumours of the orbit and ocular adnexa

Solitary fibrous tumour (SFT) is an uncommon spindle cell tumour of mesenchymal origin characterised by NAB2-STAT6 gene fusion. Although it was first described in the pleura, it can occur in connective tissue in any part of the body, but rarely presents in the orbit and ocular adnexa. SFT, which is part of the same disease spectrum as other fibroblastic tumours such as giant cell angiofibroma, haemangiopericytoma and fibrous histiocytoma, usually presents as a painless, slow-growing mass in any age group and generally follows a benign course, with a good prognosis after complete excision. However, malignant forms rarely occur. Even for benign tumours a more aggressive clinical behaviour is possible, with relentless infiltrative local growth, frequent recurrence following surgery, and malignant transformation with the potential for metastatic spread. Careful long-term follow-up is essential. The published literature on SFTs of the orbit and ocular adnexa is reviewed, and the aetiology, clinical presentation, epidemiology, radiological features, histopathology, immunohistochemistry, risk stratification, clinical management, and prognosis are discussed, reflecting on our own experience.

Carbon-ion Radiotherapy for Inoperable Solitary Fibrous Tumor of the Skull Base: A Case Report

BACKGROUND/AIM

The curative treatment for solitary fibrous tumors (SFTs) consists of surgery. However, surgery for SFTs in the skull base is difficult due to the anatomy and curative surgery may not be possible. Carbon-ion radiotherapy (C-ion RT) might be useful in the treatment of inoperable SFTs in the skull base because of its biological and physical nature. This study presents the clinical outcomes of C-ion RT for an inoperable SFT of the skull base.

CASE REPORT

A 68-year-old female patient experienced hoarseness, deafness on the right side, right facial nerve paralysis, and dysphagia. Magnetic resonance imaging revealed a tumor located in the right cerebello-pontine angle with destruction of the petrous bone, and immunohistochemical studies of the biopsy specimen showed a grade 2 SFT. Firstly, the patient underwent tumor embolization and surgery. However, 5 months after surgery, magnetic resonance imaging revealed regrowth of residual tumor. Subsequently, the patient was referred to our hospital for C-ion RT because curative surgery was unsuitable. The patient received 64 Gy (relative biological effectiveness) of C-ion RT in 16 fractions. Two years after C-ion RT, the tumor showed a partial response. The patient was still alive at the last follow-up without evidence of local recurrence, distant metastasis, or late toxicities.

CONCLUSION

These findings suggest that C-ion RT is a suitable treatment option for inoperable SFTs of the skull base.

[Research progress of intraspinal solitary fibrous tumor]

Objective

To review the research progress of intraspinal solitary fibrous tumor (SFT).

Methods

The domestic and foreign researches on intraspinal SFT were extensively reviewed and analyzed from four aspects, including disease origin, pathological and radiological characteristics, diagnosis and differential diagnosis, and treatment and prognosis.

Results

SFT is an interstitial fibroblastic tumor with a low probability of occurrence in the central nervous system, especially in the spinal canal. In 2016, the World Health Organization (WHO) used the joint diagnostic term "SFT/hemangiopericytoma" according to the pathological characteristics of mesenchymal fibroblasts, which can be divided into three levels according to specific characteristics. The diagnosis process of intraspinal SFT is complex and tedious. It has relatively variable imaging manifestations and specific pathological changes of NAB2-STAT6 fusion gene, which often requires differential diagnosis with neurinoma, meningioma, etc. The treatment of SFT is mainly resection, which can be assisted by radiotherapy to improve the prognosis.

Conclusion

Intraspinal SFT is a rare disease. Surgery is still the main treatment. It is recommended to combine preoperative or postoperative radiotherapy. The efficacy of chemotherapy is still unclear. In the future, more studies are expected to establish a systematic diagnosis and treatment strategy for intraspinal SFT.

Hemangiopericytoma of the central nervous system: a case report

Hemangiopericytomas or solitary meningeal fibrous tumors are extremely rare mesenchymal tumors. They represent only 1.6% of all central nervous system tumors, occurring mainly in adults between 40 and 50 years of age with a slight male predominance. We report the observation of a 20-year-old man treated at the Oujda Regional Oncology Center for cerebral hemangiopericytoma, revealed by headaches resistant to usual analgesic treatments without other associated signs. Initial imaging a left temporo-parieto-occipital intraaxial tumor process all responsible for a sub-falcoial and temporal engagement whose appearance first evokes a high-grade glial tumor. The patient received a complete excision whose pathological examination with immunohistochemical study was in favor of a grade III hemangiopericytoma according to the WHO 2016 classification. Therapeutic management with adjuvant radiotherapy was supplemented with a volumetric modulated arc therapy (VMAT) technique at a total dose of 54Gy. We will discuss through this case, the clinical and therapeutic peculiarities by a review of the literature.

Malignant solitary fibrous tumor of maxilla presenting as proptosis: A case report

ABSTRACT

Solitary fibrous tumor (SFT) is a fibroblastic mesenchymal neoplasm that rarely metastasizes. SFTs was first described in relation to pleura. However, occurrence of this tumor type has been reported in other sites like peritoneum, liver, adrenal gland, meninges and oral cavity. In head and neck region, oral cavity is the most common site of involvement. Most of the solitary fibrous tumors are benign and present as an asymptomatic slow growing mass. Surgery remains the mainstay of treatment. Hereby, we describe a case of 71-year-old male with malignant solitary fibrous tumor arising from right maxilla invading the right orbit presenting as proptosis.

Solitary fibrous tumors in prostate: a case report with review of the literature

BACKGROUND

Solitary fibrous tumor (SFT) is a relatively rare type of mesenchymal neoplasm that occurs most frequently in the pleura. However, SFT originating from the prostate is particularly uncommon and only approximately 39 cases were reported before. Herein, we reported a rare case of a patient diagnosed with prostate SFT and presented a literature review.Case presentation: A 50-year-old Asian with irritative urinary symptoms was admitted to our hospital and almost all the evidence indicated that benign prostate hyperplasia (BPH) caused his symptoms. Therefore, transurethral resection of the prostate (TURP) was performed, but histopathological and Immunohistochemical (IHC) assessments showed that spindle cells arranged disorderly in the TURP specimen with a cluster of differentiation 34 (CD34), B-cell lymphoma-2 (Bcl-2), and signal transducer and activator of transcription 6 (STAT6) highly expressed and SFT was diagnosed. Finally, the patient underwent a radical prostatectomy and there was no disease progression observed thereafter.

CONCLUSIONS

Prostate SFT is extremely rare, and to our knowledge, this is the first case of prostate SFT that is difficult to differentiate from small volume BPH. IHC examinations are of great diagnostic value. Radical resection of the tumor appears to be the most effective method at present and continuous follow-up is highly recommended.

Multidisciplinary Treatment of Liver Metastases from Intracranial SFTs/HPCs: A Report of Three Consecutive Cases

In the 2016 WHO classification of tumors of the central nervous system, hemangiopericytomas (HPCs) and solitary fibrous tumors (SFTs) were integrated into a new entity (SFT/HPC). Metastases to bone, liver, lung, and abdominal cavity are of concern. Only 37 cases of patients with liver metastases due to intracranial SFTs/HPCs have been reported. Herein, we present our experience in the management of patients with liver metastases from intracranial SFTs/HCPs. All consecutive patients who were treated for liver metastases from intracranial SFTs/HPCs from January 2014 to December 2020 were enrolled. Overall, three patients were treated for liver metastasis from SFTs/HPCs with curative intent. Two patients with bilobar metastases at presentation required surgical resection, transarterial embolization, stereotactic radiofrequency ablation (SRFA) and systemic therapy. One patient with a singular right liver lobe metastasis was treated with SRFA alone. This patient shows no evidence of liver metastases 39 months following diagnosis. Of the two patients with bilobar disease, one died 89 months following diagnosis, while one is still alive 73 months following diagnosis. Long-term survival can be achieved using a multimodal treatment concept, including surgery, loco-regional and systemic therapies. Referral to a specialized tertiary cancer center and comprehensive long-term follow-up examinations are essential.

Incidental finding of solitary fibrous tumor of male breast: case report and review of literature

Solitary fibrous tumor (SFT) of the breast is a rare mesenchymal tumor composed of spindle-shaped tumor cells with collagen and large blood vessels in the shape of a "staghorn". It is discovered anywhere in the human body, usually incidentally or through nonspecific symptoms. A combination of clinical, histological, and immunohistochemical features is required to establish a diagnosis. There are no proper guidelines for the treatment of SFTs because of their rarity; however, wide surgical excision remains the "gold standard". A multidisciplinary team approach is recommended. They are mostly benign with a 5-year survival rate of 89%. Following a PubMed-indexed English literature review, only six publications presenting nine cases of breast SFT in a male patient were found. The following is the case of a 73-year-old man who presented with dry cough. A SFT in the right breast was discovered incidentally during the investigative work up, and the patient was referred to our Breast Clinic at the Jules Bordet Institute, Brussels, Belgium, for appropriate treatment. The patient's presentation, imaging, and histological sample all supported the diagnosis, and he underwent uneventful surgical resection. Here, we present the first case of an incidental finding of a SFT of the male breast, with its diagnosis and therapeutic challenges.

[Clinicopathological features of spinal solitary fibrous tumor]

Objective: To investigate the clinicopathological, molecular genetic, immunohistochemical and prognostic features of spinal solitary fibrous tumor (SFT). Methods: The clinical data of 12 cases of spinal SFT in Beijing Tsinghua Changgung Hospital, Affiliated to Tsinghua University, diagnosed from January 2015 to December 2021 were collected and reclassified. The clinical data, histopathology, immunohistochemistry and molecular genetics were analyzed. Follow-up and related literature reviews were conducted. Results: Among the 12 patients, there were 5 males and 7 females; the age ranged from 31 to 73 years, with a median age of 50.5 years. All 12 cases were primary tumors, including 4 cases diagnosed at the first time and 8 recurrent cases. Among the 12 cases, 8 were WHO grade 1, 3 were WHO grade 2, and 1 was WHO grade 3. Microscopically, the spinal SFT appeared as a spindle cell tumor, the stroma was rich in many thin-walled blood vessels with various histological features such as cell morphology and necrosis according to the different tumor grade. All (12/12) of the cases expressed vimentin and STAT6 (diffuse and strong nuclear stain), 11 cases (11/12) expressed both CD34 and bcl-2, and 7 cases (7/12) expressed CD99. Next-generation sequencing showed that 12 (12/12) of the patients had NAB2-STAT6 gene fusion. The 12 patients were followed up for 6 to 80 months. There were no recurrences or metastases in the 4 first cases after operation. Among the 8 recurrent cases, 2 of the patients relapsed and 2 died. Conclusions: Spinal SFT is rare and has a high recurrence tendency. Many aspects need to be considered in the diagnosis process. STAT6 is a relatively specific marker for the diagnosis of this tumor. Complete surgical resection is the preferred treatment while postoperative radiotherapy is recommended to reduce tumor recurrence.

Solitary fibrous tumor arising from the buccal mucosa: diagnostic challenge of a rare entity

A solitary fibrous tumor (SFT) is an uncommon mesenchymal tumor characterized by spindle cell proliferation that rarely affects the oral cavity. The clinical and histopathologic features of an oral SFT are described for the benefit of dental practitioners who may encounter one of these rare cases. A 25-year-old man presented with a slow-growing swelling in the left buccal mucosa. A painless, exophytic, and well-circumscribed submucosal lesion was detected, and an excisional biopsy was performed. The biopsy specimen was submitted for histologic and immunohistochemical staining and subsequent microscopic analysis. The histopathologic examination revealed variable cellularity areas that included spindle- and star-shaped cell proliferation. These cells were immersed in a collagenized stroma containing branching vessels with a staghorn arrangement. According to immunohistochemical analysis, the tumor was characterized by STAT6, CD34, β-catenin, and Bcl-2 expression. Diagnosis of oral SFTs is challenging given that their microscopic characteristics can mimic those of malignant mesenchymal neoplasms.

CD13 is a useful tool in the differential diagnosis of meningiomas with potential biological and prognostic implications

Meningiomas are common tumors of the central nervous system. Although their histological diagnosis is usually straightforward, their differential diagnosis versus other tumors may be challenging at times. The objective of this study is to assess the diagnostic value of CD13 immunoexpression in the differential diagnosis between meningiomas and their morphological mimics. Immunohistochemical analysis for CD13, epithelial membrane antigen, SOX10, and STAT6 was carried out in a large cohort of primary meningeal tumors comprising 225 meningiomas, 15 schwannomas, and 20 solitary fibrous tumor/hemangiopericytomas. Within the meningioma group, the expression of CD13 and epithelial membrane antigen was distinguished in three categories using a semiquantitative score. Most of meningiomas expressed CD13 (94%) and epithelial membrane antigen (96%) while none of the schwannomas nor of the solitary fibrous tumor/hemangiopericytomas was positive for either the two markers. Diffuse positivity for CD13 and epithelial membrane antigen was more common in low-grade meningiomas than in anaplastic ones, which were also more often negative for such markers, especially for CD13 (32%). CD13 is a helpful immunohistochemical marker for the differential diagnosis of meningiomas and their mimics, achieving in combination with epithelial membrane antigen maximal sensitivity (100%) and showing statistically relevant difference of expression in comparison with both schwannomas (p < 0.0001) and solitary fibrous tumor/hemangiopericytomas (p < 0.0001). Furthermore, loss of CD13 expression could be related to outcome as it is associated with worrisome histological findings, mainly in the setting of anaplastic meningiomas.

Solitary fibrous tumour of the sacrum: A report of 2 cases with review of the literature

INTRODUCTION

Solitary fibrous tumour (SFT) of the sacrum is a very rare disease. So far, there have been few reports on this disease. Here, we reported 2 such cases and reviewed the other 7 reports in the literature.

CASE SERIES

Case 1, a 48-year-old man presented with lumbosacral pain for 2 months and numbness in the left plantar region for more than 1 month. The report of CT scan indicated that the sacrum was destroyed and the soft tissue mass projected into the pelvis. Histopathology showed that the cells were fusiform or short fusiform, arranged in strips, sheets, and wavy patterns. Case 2, a 40-year-old woman presented with hip joint pain and lower extremity dyskinesia for more than 2 months. The result of the MRI examination demonstrated a mass on the right sacral foramen and anterior sacrum. The characteristics of histopathology are ovoid or spindle-shaped cells with focal nuclear pleomorphism and prominently branched, hemangiopericytoma-like vascular patterns. In addition, immunohistochemical showed that CD34, Bcl-2, CD99, STAT6 and vimentin were positive, while Desmin, MSA, EMA, S100 were negative in both cases.

CONCLUSION

Previous literatures have revealed that SFTs of the sacrum are rare neoplasms. Case 1 and a part of these lesions previously reported seem to be malignant and should be treated with surgery. Radiation or chemotherapy was adopted if necessary. Since SFT of the sacrum is prone to recur and metastasis, long-term follow-up should be considered. To a certain extent, new risk stratification models can predict prognosis more accurately.

Paratesticular Solitary Fibrous Tumour Mimicking Cellular Angiofibroma: An Unusual Morphology and Rare Site

Solitary fibrous tumour (SFT) is a ubiquitous benign mesenchymal tumour of fibroblastic origin, which occurs most often in middle-aged adults. It usually presents as lung mass originating from pleura, but extrapleural occurrence is also common. Tumour is characterised by hypo- and hyper-cellular areas of spindle-shaped cells, arranged in haphazard manner with dispersed staghorn-shaped vessels. Surgical excision is the curative treatment. SFTs of the primary testicular or paratesticular region are extremely rare, but they exhibit histologic findings similar to SFTs originating at other body sites. Here, we report the case of a paratesticular SFT in a 37-year male, who presented with a non-tender, firm, mobile, left-sided retrotesticular swelling with unique histological features closely mimicking cellular angiofibroma, a common tumour of paratesticular location. Key Words: Solitary fibrous tumour, Paratesticular, benign, angiofibroma.

Solitary Fibrous Tumors of the Female Genital Tract: A Study of 27 Cases Emphasizing Nonvulvar Locations, Variant Histology, and Prognostic Factors

We report 27 solitary fibrous tumors of the female genital tract emphasizing nonvulvar locations, variant histology, and prognostic factors. The patients ranged from 25 to 78 years (most were over 40), and tumors occurred in the vulva (7), vagina (2), cervix (2), corpus (6), fallopian tube/paratubal soft tissue (5), and ovary (5). They ranged from 1.5 to 39 (mean=10.5) cm and were typically solid, but 4 were predominantly cystic. All had a haphazard arrangement of spindled to ovoid cells, with most demonstrating alternating cellular and hypocellular areas and prominent vessels, but 13 lacked hypocellular areas, and 7 had focal diffuse growth with inconspicuous vasculature. Other patterns included corded (8), fascicular (5), trabecular (1), and nested (1). Microcysts (6), myxoid background (8), hyalinization (8), lipomatous differentiation (2), and multinucleated cells (6) were also present, and 10 tumors had necrosis. Vasculature included thin-walled branching "staghorn" (27), thick-walled (7), and hyalinized vessels (5) or dilated anastomosing vascular channels (3). Nuclear atypia ranged from mild (19), moderate (7), to severe (1), and mitoses from 0 to 24/10 HPF (mean=4). STAT6 was positive in all 25 tumors tested. One tumor showed dedifferentiation; the remainder were classified as benign (19) or malignant (7) based on mitotic rate (univariate stratification model) and as low risk (14), intermediate risk (8), or high risk (4) based on the Demicco multivariate risk stratification score. Follow-up (median=23 mo) was available for 16 patients. Six tumors recurred (2 intermediate risk, 3 high risk, and the dedifferentiated tumor), 5 in the abdomen; the dedifferentiated tumor metastasized to the lung. Multivariate risk stratification was superior to univariate classification, as 5 "benign" tumors were reclassified as intermediate risk using the multivariate model; of these, 2 recurred, and 1 patient died of disease. Upper female genital tract tumors occurred in older patients, were larger, and more frequently classified as high risk compared with those of the lower tract. A trend toward increased cellularity was also seen in the upper tract tumors. Only size (P=0.04), necrosis (P=0.04), and Demicco score (P=0.01) independently correlated with recurrence. Female genital tract solitary fibrous tumors demonstrate a wide range of variant morphologies and occur in diverse sites in addition to the vulva. Tumors were often misdiagnosed as other neoplasms; thus, awareness of solitary fibrous tumors occurring at these sites is crucial in prompting staining for STAT6 to establish this diagnosis. The Demicco risk stratification system effectively predicts behavior.

[Solitary fibrous tumor/hemangiopericytoma]

Solitary fibrous tumor(SFT)/hemangiopericytoma(HPC)is a rare mesenchymal tumor with propensity for recurrence and metastasis. Although SFT and HPC were initially considered to be distinct entities, the identification of NAB2-STAT6 fusion as a definitive molecular alteration in both tumors has led to their integration into one disease entity, for both meningeal and non-meningeal lesions. This fusion leads to a nuclear relocation of the STAT6 protein and is detectable with immunohistochemistry. STAT6 immunohistochemistry has been shown to have excellent sensitivity and specificity for histological diagnosis. Although these discoveries have improved the diagnosis of SFT/HPC, the association of the NAB2-STAT6 fusion status with phenotype and prognosis remains unclear, and accurate prognostic factors have not been established. This comprehensive review provides current knowledge on the clinical, histological, and molecular characteristics of SFT/HPC.

Symptomatic Sinus Bradycardia in a Patient with Solitary Fibrous Tumor/Hemangiopericytoma Treated with Pazopanib

Pazopanib, a multi-targeted tyrosine kinase inhibitor, is associated with cardiovascular adverse events, such as hypertension, cardiac dysfunction, and thromboembolism. However, symptomatic pazopanib-related bradycardia is uncommon. We herein report a case of symptomatic bradycardia of 35 beats per minute in a patient with solitary fibrous tumor/hemangiopericytoma (SFT/HPC) treated with pazopanib for 1 month. His heart rate recovered to a normal range soon after pazopanib cessation. He restarted pazopanib at a reduced dose, which was continued without SFT/HPC progression or bradycardia recurrence. This case highlights the possibility of bradycardia induced by pazopanib and the importance of monitoring the patient's heart rate.

Cytopathology of solitary fibrous tumor: a series of 34 cases

INTRODUCTION

Solitary fibrous tumor (SFT), a fibroblastic neoplasm characterized by a specific genetic alteration (NAB2-STAT6 fusion) and relatively specific immunohistochemical profile (STAT6/CD34 positivity), is seldom the subject of cytopathology data. We report our experience with scrape smears and fine-needle aspiration (FNA) biopsies of SFT in a large patient cohort.

MATERIALS AND METHODS

A search was made of our cytopathology and surgical pathology databases for cases diagnosed as solitary fibrous tumor (SFT). FNA biopsy smears, imprint smears, and cell blocks were performed and examined using standard technique.

RESULTS

Thirty-four cases from 30 patients (M:F = 1.1:1; age range: 24-86 years, x = 58 years) met inclusion criteria for this study. All patients had prior or subsequent tissue confirmation of SFT. Twenty-seven (79%) specimens were FNAs, and 7 (21%) were scrape smears. Most cases (29, 85%) represented primary tumors, 4 (12%) were metastatic deposits, and 1 (3.5%) was a locally recurrent neoplasm. Sites included: pleura/lung 9 (26%), head/neck 8 (24%), lower extremity 7 (21%), trunk 4 (12%), intra-abdominal 3 (9%), upper extremity 2 (7%), and mediastinum 1 (4%). Mean tumor size was 7.2 cm (range: 1.5-19 cm). Three (9%) cases were diagnosed specifically as SFT. Remaining diagnoses were spindle cell neoplasm/proliferation 14 (41%), nondiagnostic 5 (15%), specific type of sarcoma 3 (9%), malignant round cell tumor 2 (6%), sarcoma 2 (6%), malignant tumor 2 (6%) and single cases of melanoma, pleomorphic adenoma, and mesenchymal tumor. Immunohistochemical (IHC) testing was performed in 7 of 27 (26%) cell blocks.

CONCLUSION

SFT FNA cytopathology is morphologically ambiguous, overlapping with a broad array of other spindle cell proliferations. A specific diagnosis is only possible with added staining of STAT6 coupled with a set of other IHC markers.

Primary solitary fibrous tumour of the prostate: A case report and literature review

INTRODUCTION

Solitary fibrous tumour (SFT) is a rare mesenchymal tumour with intermediate malignant potential. Although this tumour arises in several sites, prostatic SFT is an extremely rare neoplasm and may prove confusing owing to the lack of clinical experience because of tumour rarity. The diagnosis may be further difficult because SFTs can manifest positive immunoreactivity for CD34 and progesterone receptor, which are known markers of prostatic stromal tumours. Herein, we describe a case of prostatic SFT that was difficult to differentiate from a prostatic stromal tumour of uncertain malignant potential because of positive immunoreactivity to CD34 and progesterone receptor.

CASE REPORT

A 40-year-old Japanese man presented with lower abdominal pain. Computed tomography revealed a prostatic mass; furthermore, prostate core needle biopsy revealed proliferating bland spindle cells, without necrosis or prominent mitoses. Tumour cells were positive for CD34 and progesterone receptor on immunohistochemical analysis; thus, a prostatic stromal tumour of uncertain malignant potential was initially suspected. However, as the tumour cells showed positive immunoreactivity for STAT6, the final diagnosis was an SFT of the prostate. The patient underwent tumour resection, and at the 6-month postoperative follow-up, neither local recurrence nor distant metastasis occurred.

CONCLUSION

For an accurate diagnosis of an SFT of the prostate, STAT6 immunohistochemistry should be conducted for all mesenchymal tumours of the prostate. When STAT6 immunohistochemical analysis is unfeasible, pathologists should be aware that the morphological and immunohistochemical characteristics of SFT variable from case to case and diagnose with combined analysis of several immunohistochemical markers.

A review of solitary fibrous tumor/hemangiopericytoma tumor and a comparison of risk factors for recurrence, metastases, and death among patients with spinal and intracranial tumors

Meningeal solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) had been combined into a single classification until 2016. Recurrence and metastases rates are still understudied, especially for spinal SFT/HPCs. Here, we describe CNS SFT/HPCs and predictors for recurrence, metastases, and death, in spinal and intracranial SFT/HPCs, separately. We collected data from studies with patient-level data available on primary SFT/HPCs from multiple online databases. Clinico-demographic data, surgical outcomes, recurrence, metastases, and death rates were abstracted. We used logistic and Cox regression models to identify predictors for recurrence, metastases, and death for spinal and intracranial SFT/HPCs. Twenty-nine studies (368 patients) were included. Higher histological grade and subtotal resection were associated with recurrence (p values < 0.05), while higher histological grade and recurrence (p values < 0.005) were associated with metastases formation. Time to recurrence (p < 0.005) and metastases (p < 0.001) formation were shorter for spinal SFT/HPCs. Death rates were higher among intracranial SFT/HPC patients (p value = 0.001). Among patients with higher histological grade, rates of metastases formation were different between intracranial and spinal SFT/HPCs. Risk of metastases was higher in the first 5 years from surgery for both intracranial and spinal SFT/HPCs. Meningeal SFT/HPCs patients have high rates of recurrence and metastasis, which occur mostly within the first 5 years after diagnosis. Spinal and intracranial SFT/HPCs show similar behavior, but spinal SFT/HPCs tend to develop metastases and recurrences in a shorter interval of time. Careful follow-up for spinal SFT/HPCs should be considered because spinal cases seem to be slightly more aggressive and require more attention.

Molecular Advances in Central Nervous System Mesenchymal Tumors

Mesenchymal tumors of the central nervous system (CNS) comprise an array of neoplasms that may arise from or secondarily affect the CNS and its immediate surroundings. This review focuses on meningiomas and solitary fibrous tumors, the most common primary CNS mesenchymal tumors, and discusses recent advances in unveiling the molecular landscapes of these neoplasms. An effort is made to underscore those molecular findings most relevant to tumor diagnostics and prognostication from a practical perspective. As molecular techniques become more readily used at the clinical level, such alterations may strengthen formal grading schemes and lend themselves to treatment with targeted therapies.

Atypical/malignant solitary fibrous tumor of the pancreas with spleen vein invasion: Case report and literature review

INTRODUCTION

Solitary fibrous tumor (SFT) is an uncommon mesenchymal tumor that is most common in the pleura. However, according to previous studies, the SFT of the pancreas is extremely rare; only 20 cases have been reported so far. Here, we conduct a literature review and report the first case of atypical/malignant SFT of the pancreas with spleen vein invasion.

PATIENT CONCERNS

The patient is a 61-year-old Chinese male who presented with 1 week of upper abdominal pain. Abdominal magnetic resonance imaging showed a huge mass (>10 cm) at the distal end of the pancreas, and the mass obstructing the splenic vein.

DIAGNOSIS

Atypical/malignant SFT of the pancreas with splenic vein tumor thrombus.

INTERVENTIONS

The patient underwent laparoscopic distal pancreatectomy with splenectomy procedure to achieve a radical resection, and did not undergo chemotherapy or radiotherapy.

OUTCOMES

Abdominal computed tomography scans were performed at 1 and 4 months after resection, and no signs of recurrence or metastasis were found (. B).(Figure is included in full-text article.) CONCLUSION:: The clinical symptoms of atypical/malignant SFT of the pancreas with spleen vein invasion are not atypical, and imaging feature is lack of specificity. Preoperative diagnosis is difficult, and there is a potential for malignancy. However, due to the paucity of randomized control trials, there is no established, globally accepted treatment strategy, radiation therapy and chemotherapy regimens have not demonstrated global effectiveness, and no standardized treatments have been identified. Therefore, we recommend complete surgical resection and close clinical follow-up.

Solitary fibrous tumor/hemangiopericytoma in the cerebellopontine angle mimicking vestibular schwannoma: A case report and literature review

RATIONALE

Intracranial solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) are rare spindle cell tumors of mesenchymal origin that include benign and malignant neoplasms.

PATIENT CONCERNS

We present a 66-year-old male with a 5-year history of headache and dizziness, with left progressive sensorineural hearing loss over 1 month.

DIAGNOSES

WHO grade II SFT/HPC originating from the internal auditory canal in the left cerebellopontine angle.

INTERVENTIONS

surgical resection.

OUTCOMES

No local recurrence or metastases were observed in the follow-up 3 months after the surgery.

LESSONS

Intracranial SFTs/HPCs are rare mesenchymal neoplasms that are challenging to manage. If the imaging characteristics of tumor are not typical, clinicians should depend on tissue biopsy and immunohistochemistry to make a definitive diagnosis.

[Immunohistochemical analysis for the diagnosis of solitary fibrous tumor/ hemangiopericytoma]

The solitary fibrous tumor/ hemangiopericytoma (TFS/HP) is a rare mesenchymal extraaxial tumour. TFS/HP can sometimes be difficult to distinguish from other extra-axial tumors like meningioma, which can be clinically and radiologically indistinguishable. Molecular analysis with STAT6 (signal transducer and activator of transcription 6) nuclear expression or NAB2-STAT6 (NGFI-A binding protein 2) fusion is recommended to confirm the diagnosis. We present 3 cases, 2 women and 1 male, with pathological diagnosis of meningothelial meningioma in the first case; cases 2 and 3 with radiological suspicion of meningioma. The pathological review with molecular study certified the diagnosis of TFS/HP. For differential diagnosis between meningeal TFS/HP and meningioma, it is recommended to look for STAT6 expression as a first step, or NAB2-STAT6 fusion in order to confirm TFS/HP. The review of biopsy samples must be guaranteed in all patients, including those who were studied in Pathology Services Level 3.

Diagnosis of solitary fibrous tumor in the submandibular gland: Case report and literature review

Solitary fibrous tumors (SFTs) rarely occur in the head and neck area. Imaging findings are nonspecific, and immunohistochemical (IHC) analysis is necessary for a definitive diagnosis. We report the case of a patient with a mass in the submandibular region that was initially diagnosed as basal cell adenoma. After excision and IHC examinations, a SFT was diagnosed.

Intrapulmonary solitary fibrous tumour: a rare neoplasm of the lung and a challenging pre-operative diagnosis

BACKGROUND

Case report of a 78-year-old male who came to our observation for a growing pulmonary mass of the left upper lobe without a pre-operative diagnosis. Post-operative histopathology revealed an intrapulmonary Solitary Fibrous Tumour (SFT) of the lung.

CASE REPORT

The pulmonary lesion was an ovoid mass centrally located in the left upper lobe; it had been known and stable in size for two years; the last Chest Computed Tomography (CT) Scan highlighted a marked increase in maximum diameter (35 versus 22 mm) with contrast enhancement. In view of the growth of the lesion, the patient was referred for surgery after multidisciplinary team evaluation, although a pre-operative diagnosis had not been reached. The patient underwent Video-Assisted Thoracic Surgery (VATS) left upper lobectomy by a biportal approach. The pulmonary nodule consisted of a proliferation of bland-looking spindle cells intermingled with fibrotic stroma and alternating sclerotic and cellular areas. At immunohistochemistry, the spindle cells expressed CD34, bcl2 and CD99. A final diagnosis of intrapulmonary SFT was reached. The 36-month follow-up was negative for relapses.

CONCLUSIONS

Primary intrapulmonary SFTs are extremely rare neoplasms, generally with benign biological behaviour; surgical resection is safe and essential in order to be curative and can be achieved by a minimally invasive approach. Pre-operative diagnosis is challenging, due to aspecific clinical and radiological features.

KEY WORDS

Lung, Solitary Fibrous Tumour, Video-Assisted Thoracic Surgery Lobectomy.

Extremely rare case of intravascular solitary fibrous tumour in the inferior vena cava with review of the literature

BACKGROUND

Solitary fibrous tumour (SFT) is a mesenchymal tumour of fibroblastic type, and it develops in almost any part of the human body. However, according to previous studies, the occurrence of intravascular SFTs is extremely rare.

CASE PRESENTATION

We reported a case of intravascular SFT in a 67-year-old woman who has been experiencing swelling and pain in the right leg for 2 months. Computed tomography venography scan revealed a well-defined mass obstructing the inferior vena cava (IVC). Surgical resection was performed, and histopathologic and immunohistochemical results were consistent with SFT. Further, next-generation sequencing (NGS) analysis was performed, and results revealed two tumour-related gene mutations (deletion of PMS2 and variation of ESR1 [L536P]). The patient did not receive any adjuvant therapy, and no signs of tumour progression were observed during the 6-month follow-up.

CONCLUSION

To the best of our knowledge, this study first presented about SFT arising from the IVC and carried out an NGS analysis to validate the molecular mechanism of such condition.