Solitary fibrous tumor of the oral soft tissues: a clinicopathologic and immunohistochemical study of 16 cases

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.

Orbital Solitary Fibrous Tumors: A 20-Year Cases Series Study in a Single Center

PURPOSE

To investigate the clinical manifestations, imaging, pathology, and prognosis of orbital solitary fibrous tumors (OSFTs). In addition, the surgical incisions and the treatment outcomes were also evaluated.

METHODS

A total of 89 patients with pathologically confirmed primary OSFTs were enrolled onto this study. Clinical and histopathological characteristics, imaging data, treatment modalities, and follow-up time, including tumor recurrence and death, were documented. The outcome measures included overall survival and disease-free survival time.

RESULTS

Among 89 eligible cases, the median age of presentation was 39 years (range: 5-80 years) at the initial diagnosis. The most common presenting symptom was painless proptosis (54, 60.67%), then palpable mass (31, 34.83%), swelling (29, 32.58%), and impaired ocular motility (27, 30.34%). Tumor-related severe impaired vision was found in 11 patients (12.36%), including no-light-perception blindness (6, 6.74%), light-perception (2, 2.25%), and hand-movement (1, 1.12%). The preoperative imaging (computed tomography and magnetic resonance imaging) accurate diagnostic rate of OSFTs was 17.98% (16, 95% CI: 0.098-0.261), and misdiagnosis rate was 25.84% (23, 95% CI: 0.166-0.351). Grossly intact masses were excised for 27 patients (30.34%). Among the 89 patients, 33 (37.08%) were recurrences, and the median of these recurrent patients' interval between the first and the last operation was 7.33 years (range: 0.12-29.69 years). In 81 patients with complete follow-up data, the median course of the disease was 9.64 years (range: 1.55-33.65 years) from the onset OSFT. The overall survival rate of the 81 patients was 93.83% with a median course of 8.48 years (range: 0.38-30.4 years) from diagnosis of OSFT, and the disease-free survival rate of 81 patients was 91.36% with a median follow-up of 4.76 years (range: 0.08-19.22 years) after the last surgery. Of all the 81 patients, 5 patients (6.17%) developed local recurrence, and 3 patients (3.70%) died from tumor-related diseases, including pulmonary metastasis (2, 2.47%) and complications from intracranial lesions (1, 1.23%). Ten patients (11.24%) received postoperational radiation therapy, including 125 I seeds implantation (5, 6.17%) and external beam radiotherapy (5, 6.17%), and remained no recurrence.

CONCLUSIONS

In this series, OSFTs showed long courses and easy recurrence. Although it was very important to choose a proper surgical incision for intact resection of OSFTs at the initial surgery to avoiding recurrence, preoperative imaging is of very limited use since it is not able to identify OSFTs effectively. Postoperative radiotherapy may be beneficial to reduce the recurrence of OSFTs with malignant pathologic features.

Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

Solitary fibrous tumors (SFT) are rare mesenchymal neoplasms that account for less than 2% of all soft tissue masses. In the latest WHO 2020 Classification of Soft Tissue Tumors, extrameningeal SFT was listed as intermediate (rarely metastasizing) or malignant neoplasms. Due to the lack of characteristic clinical features, their diagnosis and treatment remain challenging. The pathogenesis of SFT is often associated with the presence of fusions of the NAB2-STAT6 gene on the 12q13 chromosome. Cytoplasmic CD34 positive staining is considerably characteristic for most SFTs; less frequently, factor XII, vimentin, bcl-2, and CD99 are present. A key factor in the diagnosis is the prevalent nuclear location of STAT6 expression. Radical resection is the mainstay of localized SFTs. In the case of unresectable disease, only radiotherapy or radio-chemotherapy may significantly ensure long-term local control of primary and metastatic lesions. To date, no practical guidelines have been published for the treatment of advanced or metastatic disease. Classical anthracycline-based chemotherapy is applicable. The latest studies suggest that antiangiogenic therapies should be considered after first-line treatment. Other drugs, such as imatinib, figitumumab, axitinib, and eribulin, are also being tested. Definitive radiotherapy appears to be a promising therapeutic modality. Since standards for the treatment of advanced and metastatic diseases are not available, further investigation of novel agents is necessary.

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 Parapharyngeal Space: A Rare Case Report

Solitary fibrous tumors are rare vascular tumours, earlier referred to as hemangiopericytoma. Their occurrence in parapharyngeal space is very rare. Hence, they should also be considered in the differential diagnosis of parapharyngeal soft tissue tumours. This case is being reported to bring out an extremely rare vascular tumour at rare site and represents a surgical challenge because of difficult access in parapharyngeal space with difficult planes between tumour and rest of parapharyngeal space, approach to it is also difficult.

Evaluation of Alternative Risk Stratification Systems in a Large Series of Solitary Fibrous Tumors with Molecular Findings and Ki-67 Index Data: Do They Improve Risk Assessment?

The clinical evolution of solitary fibrous tumors (SFTs) is often uncertain and several risk stratification systems (RSS) have been proposed. The Demicco et al. RSS is the most frequently implemented. In this study we aim to validate two alternative RSS (Sugita et al. and G-Score) using results for the Demicco RSS from a previous study of 97 SFTs. In addition, we aim to determine whether reclassified cases had any distinctive molecular features. As the Sugita et al. system substitutes mitotic count with Ki-67 index we also investigated whether Ki-67 results for tissue microarrays are comparable to those obtained using whole tissue sections. In the present study we detected that many cases classified by Demicco RSS as low-risk were reclassified as intermediate risk using the new system (G-score RSS). Kaplan-Meier survival plots for G-Score RSS showed that the low-risk and intermediate-risk SFTs had a similar evolution that contrasted with the more aggressive high-risk group. Moreover, the similar evolution in both low and intermediate-risk groups occurred despite the G-score system being stricter in classifying low-risk tumors. We observed that Sugita RSS does not provide any better risk stratification in comparison with the Demicco RSS, and testing both RSS in our series produced similar Kaplan-Meier survival data. We found some discordant results when comparing whole sections and the corresponding tissue microarrays samples, finding the hotspot areas easier to locate in whole sections. Forty-one SFTs with initial low-risk assigned by the Demicco RSS were reclassified as intermediate-risk by G-score finding both TP53 and HTER mutations in four cases, only HTER mutation in 11 cases, and only TP53 mutation in 2 cases. All six cases of SFT classified as high-risk by both the Demicco and G-score RSS suffered recurrence/metastasis, and half showed both TP53 and HTER mutations. Five SFTs were categorized as low-risk by both Demicco and G-score, of which 4 cases revealed HTER mutation. Regarding the outcome of these 5 patients, two were lost to follow-up, and one of the remaining three patients suffered recurrence. We believe that although the presence of both TP53 and HTER mutations may confer or be related to poor evolution, the isolated presence of HTER mutation alone would not necessarily be related to poor outcome. The G-score RSS more accurately identified low-risk patients than the other two risk models evaluated in the present series. Late recurrence/metastasis may occasionally be observed even in low-risk SFTs categorized by stricter classification systems such as the G-score RSS. These findings support the possibility that additional, as yet unknown factors may influence the clinical evolution of SFTs. In conclusion, given the possibility of late recurrence, long-term follow-up is recommended for all SFT patients, even in cases classified as low risk by the stricter G-score system. An integration of clinical, radiological, pathological, and molecular findings may improve SFT risk stratification and better predict patient outcome.

Solitary Fibrous Tumor of Hard Palate: A Case Report and Literature Review

Solitary fibrous tumor (SFT) is a mesenchymal tumor accounting for less than 2% of soft tissue tumors and has variable clinical behavior. It can arise in many anatomical locations of the body and in rare occasions in the oral cavity mostly in buccal mucosa and tongue. To date, a handful of such cases have been reported in the hard palate. We present a case of SFT in the hard palate of a 32-year-old man and describe the tissue morphology, immunohistochemistry workup, and follow-up together with literature review.

Solitary Extrapleural Fibrous Tumor in Salivary Glands: Our Experience-Case Series and Literature Review

(1) Background: Extrapleural solitary fibrous tumors (ESFTs) are rare oncological entities occurring in the head and neck, and even more so in the salivary glands. The clinical presentation and histologic features are usually unspecific, resulting in frequent misclassification. As an unusual tumor, ESTFs have an unpredictable clinical behavior. (2) Methods: We present two clinical cases referred to our Maxillofacial Surgery Unit for the onset of a symptomless mass involving, in one case, the parotid gland, and in the other case, the sublingual gland. (3) Results: Solitary fibrous tumors could be considered as neoplasms with intermediate biological behavior that are not entirely predictable on the basis of morphological features, as these are mostly still unknown. However, a few histologic, immunohistochemical, and imaging features, such as a hypodense signal at the T1 sequence in an MRI, or positivity for CD34, bcl2, and CD99, and the NAB2-STATS6 fusion gene, could be useful for an early differential diagnosis of ESTFs. (4) Conclusions: All patients were alive at follow-up with no evidence of disease. Surgical management should always be considered as the first choice for oncological radicality, and clinical behavior should always be defined with the help of the study of radiological and anatomopathological features.

Solitary Fibrous Tumors of the Head and Neck: A Single-Institution Study of 52 Patients

Objective

To evaluate the clinicopathologic characteristics of head and neck solitary fibrous tumors and features that may predict tumor recurrence.

Study Design

Retrospective review.

Setting

University of California–Los Angeles Medical Center.

Methods

A single-center retrospective study was conducted on pathologically confirmed cases of head and neck solitary fibrous tumors between 1996 and 2021. Patient demographics, clinical course, and histopathologic features were evaluated. Recurrence-free survival was estimated via Kaplan-Meier analysis.

Results

A total of 52 patients were reviewed. The average patient age was 54.7 years (range, 15-89). The most common subsite was the orbit (53.8%, n = 28), but other involved areas included the nasopharynx, paranasal sinuses, and scalp. The median tumor size was 2.95 cm (range, 1.3-11.2). Strong STAT6 (100%) and CD34 (97.9%) expression was observed on immunohistochemistry. Almost all patients were initially managed with wide local excision; 82% of patients (n = 14) had positive margins on pathologic review; and 15% (n = 4) had recurrence at a median 28.5 months (range, 10-113). White patient race was the only significant predictor of tumor recurrence. Patient age (≥55 years), tumor size (≥4), high mitotic rate, and disease subsite were not associated with recurrence.

Conclusion

Head and neck solitary fibrous tumors demonstrate a significantly larger local recurrence rate as compared with their rate of metastasis. They can recur many years following initial therapy, warranting long-term surveillance and follow-up to assess for tumor recurrence.

Solitary fibrous tumors: Clinical and imaging features from head to toe

Solitary fibrous tumors (SFTs) are rare fibroblastic mesenchymal tumors that are usually benign with variable malignant potential. They can develop in any organ due to their spindle cell origin. The exact etiology of solitary fibrous tumors is unknown. The majority of SFTs are benign with 10-30% of them exhibiting aggressive and malignant features. The aggressiveness of this type of tumor is not associated with its histological features, which makes surgical resection the treatment of choice. We will review the clinical and radiological features and possible differential diagnoses of SFTs according to their anatomical sites following the World Health Organization 2020 classification.

Cellular solitary fibrous tumor in the mental area: a case report and literature review

Solitary fibrous tumors (SFTs) are rare benign mesenchymal tumors that occur mainly in the pleura. We herein report the first case of a cellular SFT located in the mental region of the head and neck in a 46-year-old woman. Facial computed tomography revealed a mass measuring 0.8 cm with clear boundaries in the right mental region. After excision of the mass, expert pathologists diagnosed a cellular SFT. To our knowledge, this is the first case of a cellular SFT identified in the subcutaneous tissue of the mental region of the head and neck. Because the postsurgical prognosis of SFTs is unpredictable, long-term follow-up and further studies are necessary to determine the characteristics of cellular SFTs in the head and neck region.

Oral Solitary Fibrous Tumor: A Retrospective Clinico-Pathological Study and Long-Term Follow-Up

Background and Objectives: This was a retrospective single-center study to analyze and describe the clinical and histological features of all cases of oral solitary fibrous tumor (SFT). Study design: the study included all consecutive cases of oral SFT diagnosed between 2008-2018 at a single tertiary center. Materials and Methods: Clinical data was retrieved from medical charts. The diagnosis of oral SFT was based upon the morphologic features of the lesions, in routine hematoxylin and eosin (H&E) stained sections and confirmed by immunohistochemical analyses including CD34, CD99, Bcl2, and stains for STAT6. Results: Seven cases of oral SFT were found. Of these, three (42%) were in males and four (58%) in females. The age range was 24-63 years (mean 47 ± 13). Four (58%) lesions were located in the buccal mucosa, two (28%) in the labial mucosa and one (14%) on the floor of the mouth. The diameter ranged between 3-50 mm (mean 22 ± 14 mm). All patients were treated with local excision. Follow-up periods were between 2-74 months (mean 41 ± 27). No recurrences were reported. Conclusions: We present a series of oral SFT, which were all non-aggressive in presentation and did not recur after conservative surgery (local excision) over a relatively long follow-up period.

Clinicopathologic Analysis of Oral and Maxillofacial Solitary Fibrous Tumor

OBJECTIVES

The aim of this systematic review was to provide an overview of the oral and maxillofacial solitary fibrous tumor (SFT) in order to determine its clinicopathologic characteristics and biological behavior.

METHODS

We conducted a systematic review in May 2019 in multiple databases. Cases diagnosed as SFT in the oral cavity and maxillofacial complex were included.

RESULTS

Seventy-three published articles were included in our systematic review, corresponding to a total of 154 cases. SFT showed a slight female predilection (53.2%), and the cheek mucosa/cheek, tongue, and palate were the most affected anatomical sites. The mean size of SFT in the oral cavity and maxillofacial region at diagnosis was 1.4 cm. Histologic features of malignancy by morphologic analysis (P < .001) were significantly associated with a larger tumor size. Surgical excision was the most frequent therapeutic modality. Recurrence and metastasis were uncommon findings in our sample.

CONCLUSIONS

Histologic features of malignancy can be important parameters of tumor behavior. Adequate surgical treatment and long-term follow-up are required for these cases.

Solitary Fibrous Tumor Arising in the Buccal Space

A 39-year-old Japanese woman presented to the Department of Oral and Maxillofacial Surgery, Okayama University Hospital, with the complaint of a slowly growing buccal mass. The mass was well defined, had rounded margins, and was free from skin and muscles. A color Doppler echographic examination indicated high flow velocity of the blood surrounding the mass. Contrast-enhanced images on CT and contrast-enhanced T1-weighted images on MRI displayed a homogeneous enhanced mass with a well-defined margin. A fine-needle aspiration biopsy and histological examination were performed. On immunohistochemistry, spindle cells were strongly positive for CD34, STAT6, and vimentin and negative for EMA, S100, and α-SMA. The tumor was removed with extracapsular dissection. The tumor was composed of bland spindle cells proliferating in a patternless arrangement with a collagenous background. Most of the tumor mass consisted of hypocellular areas including ectatic blood vessels. A prominent branching vascular pattern was observed. Immunohistochemistry demonstrated that the tumor cells were positive for CD34, STAT6, vimentin, and Bcl-2, and negative for α-SMA, S100, and EMA. Three mitotic cells were observed per 10 high-power fields, and the Ki-67 index was 5.7%. The morphological and immunohistochemical features were consistent with a diagnosis of solitary fibrous tumor.

Papillary Solitary Fibrous Tumor/Hemangiopericytoma: An Uncommon Morphological Form With NAB2-STAT6 Gene Fusion

Solitary fibrous tumor/hemangiopericytomas (SFT/HPCs) are mesenchymal tumors characterized by "staghorn" blood vessels and collagen deposition. Little is known about SFT/HPCs with papillary architecture. We summarized the clinicopathologic features of 12 patients with papillary SFT/HPCs (8 males and 4 females; median age: 59 years), including 8 previously reported cases. Tumors were present in the meninges (75%, 9/12), adrenal gland (8%, 1/12), orbit (8%, 1/12), or spinal canal (8%, 1/12). Six tumors (50%) had a true papillary architecture with fibrovascular cores and 6 tumors (50%) had a pseudopapillary architecture with vascular cores. Nuclear staining for STAT6 was present in all tested tumors (10/10). RT-PCR indicated NAB2 ex6-STAT6 ex17 fusion in 4 tumors (80%, 4/5) and NAB2 ex4-STAT6 ex2 fusion in 1 tumor (20%, 1/5). Five patients (42%, 5/12), all with tumors in the meninges, developed local recurrence at a median of 61 months after surgery (range: 56-165 months; mean: 88.6 months). These results indicated that the papillary architecture is a morphological form of SFT/HPCs. The recognition of this pattern, with appropriate immunohistochemical analysis and assessment of NAB2-STAT6 fusion, should facilitate the distinction of these rare neoplasms from morphologically similar tumors in the meninges, lung, pleura, and soft tissue.

Extrapleural solitary fibrous tumor: A distinct entity from pleural solitary fibrous tumor. An update on clinical, molecular and diagnostic features

Solitary fibrous tumor (SFT) is a mesenchymal neoplasm that was originally described to be localized in the pleura, but thereafter, this has been reported in several anatomic sites. Although the etiology of the neoplasm remains largely unknown, the pathogenesis seems to be related to an NAB2-STAT6 fusion gene due to paracentric inversion on chromosome 12q13. The diagnosis of extrapleural SFT is challenging, owing to its rarity, and requires an integrated approach that includes specific clinical, histological, immunohistochemical, and even molecular findings. Histologically, extrapleural SFT shares morphological features same as those of the pleural SFT because it is characterized by a patternless distribution of both oval- and spindle-shaped cells in a variable collagen stroma. In addition, morphological variants of mixoid, fat-forming, and giant cell-rich tumors are described. A correct diagnosis is mandatory for a proper therapy and management of the patients with extrapleural SFT, as extrapleural SFT is usually more aggressive than pleural form, particularly cases occurring in the mediastinum, retroperitoneum, pelvis, and meninges. Although SFT is usually considered as a clinically indolent neoplasm, the prognosis is substantially unpredictable and only partially related to morphological features. In this context, cellularity, neoplastic borders, cellular atypias, and mitotic activity can show a wide range of variability. We review extrapleural SFT by discussing diagnostic clues, differential diagnosis, recent molecular findings, and prognostic factors.

Magnetic resonance features of meningeal solitary fibrous tumors

The aim of the present study was to investigate magnetic resonance (MR) features of meningeal solitary fibrous tumors (SFTs) in order to improve their recognition. The study retrospectively analyzed MR manifestations in 12 cases of meningeal SFTs confirmed by surgery. The lesions were analyzed in terms of the site of their growth, growth mode, morphology, size, changes in the MR signal and the edge of the focus. The tumors were malignant in 3 cases, benign in 7 cases and borderline in 2 cases. A total of 3 cases spanned the tentorium cerebelli, 3 spanned the falx and another case was close to the falx. Overall, 4 superficial tumors were accompanied by adjacent bony destruction. One case was located at the triangular area created by the right lateral ventricles. The tumors were all lobular, with a large diameter and more cystic areas in the center of the focus. The signals were often heterogeneous. The parenchyma in the tumors was significantly enhanced. For certain tumors, the signal was usually inhomogeneous and not uniform. The MR features of a SFT were often similar to other intracranial tumors and easily misdiagnosed. There were certain innate characteristics, for example, the tumor was often a solitary large soft-tissue mass with an irregular edge and a clear boundary, with a lobulated contour, and was widely involved with other tissues. The tumors often grew across either the falx or tentorium cerebelli. A significantly inhomogeneous signal was found and either a low or low-high mixed signal on T2-weighted images in particular. These features are useful for the differential diagnosis of SFTs and other tumors.

Solitary fibrous tumor of the floor of the mouth

BACKGROUND

A solitary fibrous tumor (SFT) of the oral cavity is an extremely rare entity. Its diagnosis is complicated because of its diverse morphology and similarity to other mesenchymal diseases.

CASE REPORT

A rare case of SFT involving floor of the mouth is presented. The tumor was well circumscribed and almost spherical, measuring approximately 3 cm in diameter. Patient was submitted to biopsy and histopathologic examination showed a tumor composed of spindle to epithelioid cells showing pale to eosinophilic cytoplasm, oval or elongated nuclei with inconspicuous nucleoli. Tumor cells showed strong positivity for CD34, vimentin and Bcl-2. SFTs may present as a diagnostic challenge. The patient was followed for 8 years without recurrences.

RESULTS

SFT is an uncommon disease in maxillofacial region; however it should be considered in the differential diagnosis of spindle cell neoplasms with oral manifestation. Only a few cases have been reported in the floor of mouth. We describe a new case of SFT arising at this location. Key words:Solitary fibrous tumors, mouth floor, oral diagnosis.

CD34 + tumours of the orbit including solitary fibrous tumours: a six-case series

Background

To report six cases of CD34+ fibroblastic mesenchymal tumours, which are uncommon neoplasms in the orbit.

Case presentation

Six patients presenting with proptosis and palpable mass who were later diagnosed with fibrous solitary tumours, fibrous histocytoma or haemangiopericytoma in the orbit were included. All patients received radiologic examinations and surgical excision for histopathology and immunohistochemistry examinations. Five patients had no recurrence after a minimum follow-up of 12 months. One patient (case 6) experienced recurrence twice, and had debulking surgeries each time. At present, the patient still has remnant tumour in the orbit, but no growth has been detected during the past two years. The tumour size will be closely monitored.

Conclusions

Even though fibroblastic tumours are rarely found in the orbit, they can present as a palpable mass with proptosis. Complete surgical excision is important for long-term prognosis, and immunohistochemical study is helpful for confirming pathologic diagnosis.

Solitary Fibrous Tumors: 2016 Imaging Update

Optimal management of solitary fibrous tumor requires a multidisciplinary approach with proper histopathological mapping and use of various imaging modalities for exact delineation of primary tumor and metastatic disease if present. In this article, the authors present a comprehensive review of the spectrum of imaging findings of solitary fibrous tumors involving various organ systems and discuss the role of molecular targeted therapies in the management of metastatic disease.

Mesenchymal neoplasms of the head and neck: a cytopathologic analysis on fine needle aspiration

INTRODUCTION

Fine-needle aspiration (FNA) is commonly used to diagnose mass lesions discovered in the head and neck (H&N). Soft tissue neoplasms (STNs) are less common than epithelial tumors in this anatomic zone and often cause diagnostic difficulty when encountered in routine practice. In this study, we examine the frequency of H&N STNs at our institution and describe their cytomorphologic characteristics and clinical correlates.

METHODS

115 FNA specimens from 115 patients with STN of the H&N region were identified (2005-2015) from archives of The Johns Hopkins University Hospital. When available, slides from these cases were reviewed and any corresponding clinical and radiologic data was evaluated.

RESULTS

A total of 95 (83%) STNs were found to be primary to the H&N region and 20 (17%) were metastatic from distant sites. Of these 95 cases, 58 (61%) primary lesions were benign and 37 (39%) were malignant. The most common STNs were benign nerve sheath tumors, representing 40 (35%) cases: 30 schwannomas, 4 neurofibromas, and 6 were not further classified. The most aggressive neoplasms in terms of clinical outcome were leiomyosarcoma, Ewing sarcoma, synovial sarcoma, and chondrosarcoma. In 35 (60%) of the malignant cases and 25 (54%) of the benign cases a subsequent surgical resection was performed.

CONCLUSIONS

H&N can be involved by a wide range of primary and metastatic STNs. benign nerve sheath tumors are the most common STNs found on FNA in this region. Although not always definitively diagnostic, FNA of STNs can often provide a differential diagnosis that can help guide the need for an excision and/or further treatment.

Metastatic Intracranial Hemangiopericytoma to the Spinal Column: A Case Report

Intracranial hemangiopericytoma (HPC) is a rare brain tumor with aggressive biologic behavior associated with high recurrence rate and often with extracranial metastasis. The most common sites of extracranial metastasis of the intracranial HPC are the long bones, lung, liver and abdominal cavity in the order of frequencies. Extracranial metastases usually occur long after the initial diagnosis of the primary tumor. Metastatic intracranial HPC to the vertebra has been rarely reported. We present a case of intracranial HPC metastasized to the L2 vertebral body 13 years after multiple surgical resections and radiotherapy of the primary intracranial HPC.

Giant Solitary Fibrous Tumor of Orbit

Solitary fibrous tumors (SFTs) have been reported in various locations in the body. Solitary fibrous tumors are extremely rare tumors, especially when located in the orbit. Diagnosis of SFT cannot be made based on histopathology only because it exhibits a variable microscopic appearance, and necessitates immunohistochemistry to confirm the diagnosis. A 51-year-old man was admitted to our clinic for the evaluation of a mass bulging in his left eye. Clinical examination revealed a painless mass extruding out of the orbital cavity with dimensions of 8 × 7  cm. Exenteration of the left eye including the upper and lower eyelid and reconstruction of the orbital cavity using a temporoparietal fascia flap and a temporal muscle flap was performed. SFT of orbital region is known as a slow growing and painless tumor. Based on previous studies, increased mitotic rate of the tumor gives the impression that the tumor has a malignant nature. Until now a small number or orbital SFTs were reported and none of them presented with a giant mass protruding out of the orbital cavity. We present a unique case of orbital SFT filling the whole orbital cavity and protruding outward as a giant mass. This case has been reported to expand our knowledge in this debated entity.

Intracranial solitary fibrous tumors: A report of two cases and a review of the literature

Solitary fibrous tumors (SFTs) are uncommon, with the pleura as a site of predilection. Central nervous system SFTs, particularly intracranial SFTs, are extremely rare. The lesions are generally benign and localized, and surgery is the main therapeutic solution. The current study reports the cases of a patient who presented with right haunch pain, right leg weakness and paresthesias for several months, and a patient with a history of unexpected loss of consciousness. Magnetic resonance imaging revealed the presence of lesions, with a spindle cell morphology evident on pathological examination. The immunohistochemical examination demonstrated a strong immunoreaction for cluster of differentiation 34, which supported the diagnosis of an SFT. Following a near-total resection, the patients had a good neural prognosis. The present study also provides a literature review, discussing the imageological and pathological characteristics of SFT, and the diagnostic methods that aid in distinguishing the entity from other spindle-cell central nervous system tumors.

Clinicopathologic and immunohistochemical features of five new cases of solitary fibrous tumor of the oral cavity

OBJECTIVE

To describe the clinicopathologic and immunohistochemical features of five cases of oral solitary fibrous tumor.

STUDY DESIGN

Clinical data were collected from charts of two oral pathology laboratories of Latin America. All cases were evaluated by conventional hematoxylin and eosin staining and an extended immunohistochemical panel comprising vimentin, CD34, CD99, bcl-2, HHF-35, smooth muscle actin, calponin, S-100 protein, h-caldesmon, and Ki-67.

RESULTS

The study included 1 male (20%) and 4 female (80%) patients, with a median age of 43 years. The most common affected site was the buccal mucosa (40%). Tumors were characterized by proliferation of spindled and ovoid cells in a variably vascular and collagenized stroma. All tumors were positive for vimentin, CD34, bcl-2, and CD99. Recurrence was not observed after complete surgical enucleation.

CONCLUSIONS

Oral solitary fibrous tumors usually appear as well-delimited submucous nodules with a firm-rubbery consistency and covered by intact mucosa. Immunoreactivity for CD34, bcl-2, and CD-99 is helpful to confirm the diagnosis.

A Rare Tumor of the Retropharyngeal Area: Solitary Fibrous Tumor

We describe a case of retropharyngeal solitary fibrous tumor (SFT) in a 46-year-old female patient. Total removal of the tumor without any complications was performed by transoral surgery. Intraoral resection of retropharyngeal SFT can be preoperatively performed by meticulous assessment of the extent and vasculature of the tumor with radiological guidance.

Head and neck solitary fibrous tumors: a rare and challenging entity

The objective of this study is to analyze the outcome of treatment for solitary fibrous tumors (SFTs) in the head and neck area. SFTs present as slow-growing masses, often with local compressive symptoms that are difficult to distinguish from other soft-tissue tumors. SFTs are commonly treated using local excision without adjuvant therapy. To date, only heterogeneous small series have been published, documenting the treatment results and outcome with these tumors. Retrospective study of patients with histopathologically confirmed SFT treated at two tertiary referral hospitals between 2004 and 2014. Eight men and four women with histologically confirmed SFT were identified in the records. Their age range was 37-82 years (mean 57.8 years). The mean follow-up period for eight patients was 6.75 years (range 1-24 years). Four patients were lost to follow-up. Sublocalizations were neck (n = 3), orbit (n = 2), paranasal sinus (n = 2), cheek (n = 2), hard palate (n = 1), parotid gland (n = 1), and tongue (n = 1). The first-line treatment for all of the tumors identified was surgical excision. In four cases, the surgical margins were narrow or unclear due to piecemeal resection in the paranasal sinus and orbit (n = 3) or a tumor location deep in the parapharyngeal space (n = 1). Recurrences developed in two of these cases (in the orbit and parapharyngeal space), and the other two patients were lost to follow-up. Radiotherapy and chemotherapy were not administered as first-line treatments. Overall, the local recurrence rate (n = 2/8) was 25 %. The disease-specific survival rate was 100 %. These results are consistent with the literature data and show that safe surgical excision, without opening of the tumor capsule, reduces the risk of local recurrence and leads to a favorable outcome. Tumors in the head and neck often represent a surgical challenge, and wide surgical margins are rarely possible due to the complex three-dimensional anatomic compartments in the region. Head and neck surgeons should therefore be aware that there is an increased risk of recurrence in these patients; tightly scheduled follow-up visits are mandatory for at least 10 years, if not longer. Radiotherapy only appears to be an option in patients with unresectable tumors or when wide surgical excision would cause severe functional morbidity.

CT features of retroperitoneal solitary fibrous tumor: report of three cases and review of the literature

CT findings in three cases with solitary fibrous tumors (SFTs) confirmed by histopathology and immunohistochemistry were reviewed retrospectively, and compared with pathological results. The three tumors were large, well-defined, and smooth contour masses and SFT consisted of solid components of two different densities. On enhanced CT scans, tumors were strongly enhancing, the multiple vascular shadows were seen within the tumor in the arterial phase. There is progressive enhancement from the arterial to the venous phase, and the tumor capsule can be observed. Histologically, the tumors are composed of spindle cells within a background of collagen stroma, and showed a wide range of growth patterns, alternating hypercellular (tumor cell-rich) and hypocellular (collagen-rich) areas. The diagnosis is confirmed by characteristic positive immunohistochemical staining for CD34.

Spindle cell lipoma of the tongue: a clinicopathologic study of 8 cases and review of the literature

Spindle cell lipoma is a histologically distinct variant of lipoma characteristically arising in the subcutis of the posterior neck, upper back, or shoulder. Spindle cell lipomas infrequently occur within the oral cavity and, in particular, rarely involve the tongue. The clinical and pathologic features of eight cases of spindle cell lipoma affecting the tongue were analyzed. The study group included five men and three women ranging in age from 35 to 80 years (mean 57.4 years). Most lesions presented as either a painless or slowly growing lingual mass. The tumors were well circumscribed and characterized microscopically by a mixture of mature adipocytes, cytologically bland spindle cells, and interspersed bundles of thick collagen fibers in variable proportions. Myxoid stroma was a prominent feature in three lesions. The spindle cells were positive with CD34, while negative with S-100 protein, desmin, and smooth muscle actin. Treatment consisted of local excision in all cases. There have been no recurrences to date, with clinical follow up information available for all patients (range 11-118 months; mean 50.8 months). Lingual examples of spindle cell lipoma should be distinguished from other fat containing spindle cell neoplasms that can arise at this anatomic site.

Spindle cell lipoma of the tongue: a clinicopathologic study of 8 cases and review of the literature

Spindle cell lipoma is a histologically distinct variant of lipoma characteristically arising in the subcutis of the posterior neck, upper back, or shoulder. Spindle cell lipomas infrequently occur within the oral cavity and, in particular, rarely involve the tongue. The clinical and pathologic features of eight cases of spindle cell lipoma affecting the tongue were analyzed. The study group included five men and three women ranging in age from 35 to 80 years (mean 57.4 years). Most lesions presented as either a painless or slowly growing lingual mass. The tumors were well circumscribed and characterized microscopically by a mixture of mature adipocytes, cytologically bland spindle cells, and interspersed bundles of thick collagen fibers in variable proportions. Myxoid stroma was a prominent feature in three lesions. The spindle cells were positive with CD34, while negative with S-100 protein, desmin, and smooth muscle actin. Treatment consisted of local excision in all cases. There have been no recurrences to date, with clinical follow up information available for all patients (range 11-118 months; mean 50.8 months). Lingual examples of spindle cell lipoma should be distinguished from other fat containing spindle cell neoplasms that can arise at this anatomic site.

MRI findings of solitary fibrous tumours in the head and neck region

OBJECTIVES

To analyse the MRI findings of solitary fibrous tumours in the head and neck region.

METHODS

We retrospectively reviewed MR images in eight patients with solitary fibrous tumours proven on histological examination. All the patients underwent conventional MRI, and four patients also underwent dynamic contrast-enhanced MRI and diffusion-weighted imaging in five cases. Image characteristics were analysed.

RESULTS

All lesions were found as solitary well-defined masses ranging in size from 1.9 to 6.8 cm (mean, 4.1 cm). They were mostly homogeneous and isointense to the muscle on T1 weighted images and heterogeneous and mildly hyperintense on T2 weighted images. After gadolinium administration, areas that were mildly hyperintense on T2 weighted images were strongly enhanced. They were mildly hyperintense on diffusion-weighted imaging. The average tumour-apparent diffusion coefficient values were 0.001 157 ± 0.000 304 9 mm s(-2) compared with the muscle 0.000 760 ± 0.000 265 0 mm s(-2), and there was a statistical difference of p = 0.002. The time-intensity curves exhibited a rapidly enhancing and a slow washout pattern on dynamic contrast-enhanced MRI.

CONCLUSIONS

Solitary fibrous tumours should be considered in cases of heterogeneous hypervascular tumours in the head and neck region. Areas of mild hyperintense intensity on T2 weighted images that are strongly enhanced after gadolinium injection are suggestive of this diagnosis. Non-restricted diffusion and rapidly enhancing and slow washout pattern time-intensity curves may be additional valuable features.

Solitary fibrous tumor of the larynx: case report demonstrating the value of MRI in guiding surgical management

A 74-year-old woman presented with persistent dysphagia, dysphonia, and throat gurgling. Prior intraoperative biopsies were negative, and outside imaging revealed supraglottic swelling. Magnetic resonance imaging (MRI) demonstrated a well-defined T1 and T2 hypointense, avidly enhancing hypopharyngeal mass. Deep intraoperative rebiopsies revealed a tumor with CD34+ tissue, diagnostic of a solitary fibrous tumor. A broad range of nonsquamous cell tumors should be considered when a submucosal laryngeal mass is encountered. MRI may be particularly helpful in guiding appropriate biopsy.

Solitary fibrous tumor of the buccal vestibule: report of two cases

Solitary fibrous tumor (SFT) is a rare benign tumor that occurs most frequently in the pleura. It is considered rare in the maxillofacial area. Two new cases of SFT of the buccal vestibule are reported. The previously reported cases of oral SFT are reviewed. The tumors were composed of spindle-shaped cells that were arranged haphazardly and were positive for CD-34, BCL-2, CD-99 and vimentin. Although rare, SFT should be included in the differential diagnosis of oral soft tissue tumors. The clinical presentation and imaging can provide the clinician a better tool for preoperative diagnosis.

Solitary fibrous tumor of the hypopharynx: case report and literature review

Solitary fibrous tumors are rare mesenchymal neoplasms that are increasingly being described in the head and neck. Clinical presentations may include compression by these tumors on vital surrounding structures. While malignant transformation is rare, treatment entails wide local excision. We present the case of a 74 year-old female with an increasingly enlarging symptomatic hypopharyngeal solitary fibrous tumor that was found on carotid duplex ultrasound. Transoral surgical excision resulted in relief of symptoms. Treatment options are discussed and a literature review of this uncommon disorder presented.

Solitary fibrous tumor: an update on the spectrum of extrapleural manifestations

Solitary fibrous tumor (SFT) is a rare tumor initially believed to be a benign localized pleural tumor of mesothelial origin. Over the past few years, the literature on this tumor has grown tremendously. The tumor is now reported in diverse bodily locations, and recognized to have a wider range of clinical and radiological features. The most common extrapleural sites of the tumor are the orbits and the extremities. Tumors are often well-circumscribed masses, and vary in size from 1 cm to over 30 cm. The admixture of histological components in the tumor, namely, fibrous tissue, cellular components, and highly vascularized areas consisting of numerous closely packed small to medium-sized blood vessels, influence the imaging appearances of the tumor. On magnetic resonance imaging (MRI), the diagnosis of solitary fibrous tumor is suggested by a well-circumscribed mass that has smooth margins, and focal or diffuse hypointense signal on T2-weighted imaging due to fibrous content in the tumor. SFTs demonstrate strong focal or diffuse contrast enhancement due to the highly vascularized areas in the tumor.