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

Incidental solitary fibrous tumor involving the seminal vesicle: A case report

Solitary fibrous tumors are rare mesenchymal neoplasms that can range from slow-growing to aggressive tumors. This report presents a unique case of a young male patient with a solitary fibrous tumor involving the seminal vesicle, a rare location, and reinforces incidental discovery of these tumors on imaging and physical exams. Detection of these tumors is imperative to identify and treat malignancy. In our case, a 39-year-old previously healthy Asian male presents to the emergency department as a trauma admission post bicycle crash and is incidentally found to have a pelvic mass on computed tomography imaging of the pelvis. The patient underwent trans-anal biopsy which showed spindle epithelioid cells positive for CD34 and STAT6 markers, with a morphological and immunohistochemical profile consistent with a solitary fibrous tumor. The patient underwent surgery with a robotic-assisted laparoscopic pelvic mass resection and now follows up annually with imaging for observation.

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.

Solitary Fibrous Tumor of the Prostate Treated with Frozen-Section Supported Robot-Assisted Nerve-Sparing Radical Prostatectomy

INTRODUCTION

Solitary fibrous tumors (SFTs) of the prostate are extremely rare. We report on a 60-year-old man who was diagnosed with prostatic SFT through transurethral resection (TUR) of the prostate, and we provide a narrative literature review to put the case into perspective. We looked into multiple databases for articles published before June 2022.

CASE REPORT

A 60-year-old man without comorbidities presented with acute urinary retention and significant macrohematuria. Due to recurrent bladder tamponades and relevant blood loss despite irrigation, an emergency endoscopic transurethral evaluation was initiated. Intraoperatively, diffuse venous hemorrhage from prostatic vessels around the bladder neck was detected, as well as significant hemorrhage from a grossly enlarged and tumor-suspicious prostate middle lobe. Within the framework of extensive bipolar coagulation, parts of the suspicious middle lobe were removed via TUR. The final histopathology report showed incompletely resected SFT of the prostate. Due to the extremely rare SFT diagnosis, the case was discussed in an interdisciplinary tumor board and further diagnostic workup, including thoracoabdominal computed tomography and magnetic resonance imaging of the pelvis, was performed, which revealed no secondary tumors or signs of metastasis. According to the tumor board recommendation, robot-assisted radical prostatectomy (RARP) with bilateral nerve sparing was performed, supported by intraoperative frozen section. The final histopathology confirmed the SFT that had developed from the transition zone. The SFT was resected with negative frozen section result and negative surgical margins (R0). No intra- and perioperative complications occurred, and in the short-term follow-up, the patient presented in excellent general status with full continence. From 1997 to June 2022, we identified a total of 12 publications reporting on treatment for prostatic SFT (11 case reports and 2 patient series), with none performing bilateral nerve sparing, frozen section, or robot-assisted radical prostatectomy. No common survival endpoints were accessible.

CONCLUSION

This case demonstrates the exceedingly rare case of SFT of the prostate, which has been described in the literature in only 23 men worldwide. Here, we were the first to demonstrate the feasibility of bilateral nerve-sparing RARP supported by frozen section. A systematic review was not possible due to the lack of common endpoints.

A multicentre retrospective study on extra-thoracic solitary fibrous tumour: preoperative MRI findings predict intraoperative findings and postoperative prognosis

OBJECTIVE

The present study investigated the relationships between the preoperative and operative findings of solitary fibrous tumour (SFT) and between preoperative findings and prognosis.

METHODS

We reviewed 50 SFT patients treated at our musculoskeletal oncology hospital group. We analyzed preoperative clinical findings, particularly MRI imaging findings, and intraoperative information as well as the relationship between preoperative findings and outcomes.

RESULTS

Mean age was 48.9 years and the mean follow-up was 51.8 months. Prior to surgery, needle biopsy was performed on 27 patients and open biopsy on 14. T2-weighted images showed a high signal intensity in 24 patients and heterogeneous signal intensity in 20. Tumours had polylobular contours in 17 patients and smooth and round contours in 27. Collateral feeding vessels were detected in 22 patients. Gd-enhanced MRI was performed on 23 patients, and showed 15 with homogeneous enhancement and 8 with heterogeneous enhancement. Surgical times were significantly longer in patients with a retroperitoneal origin, a tumour of 10 cm or more, and polylobular-type tumours. Intraoperative blood loss was significantly greater in patients with a retroperitoneal origin and heterogeneous Gd-MRI-enhanced tumours. In histopathological evaluations, surgical margins were positive in 12 patients. Local recurrence was observed in one patient. Distant metastasis was noted in eight patients, four of whom had pulmonary metastases. Positive surgical margins were more common in polylobular-type tumours. Distant metastases were more likely to appear in patients with observable collateral feeding vessels and heterogeneous Gd-MRI enhancement.

CONCLUSION

The present results suggest that preoperative clinical findings in SFT patients predict longer surgical times and the risk of increased intraoperative blood loss. Moreover, the risk of a positive surgical margin and postoperative distant metastases may be predicted based on preoperative MRI.

Solitary Fibrous Tumor of the Shoulder Metastasizing to the Small Intestine Presenting as Intussusception: A Case Report

Solitary fibrous tumors (SFTs) are rare vascular malignancies that are rarely reported in the upper limb, and even rarer as secondary metastasis to the small bowel. We present a case of a 39-year-old male patient, a known case of metastatic SFT, presenting with severe abdominal pain and vomiting. Computed tomography showed ileo-ileal intussusception. Subsequently, he underwent surgical resection. Histopathological examination showed high-grade sarcoma of the intestinal wall, confirming small intestinal metastasis. This constitutes one of the rare cases of SFTs metastasizing to the small bowel, specifically to the ileum. A review of the literature on similar cases is presented. There appears to be a connection between upper limb SFT and bowel metastasis according to reported literature. However, the scarcity of similar reports makes the generalizability of the conclusion limited.

Solitary Fibrous Tumor of the Bone Detected by FDG PET/CT

ABSTRACT

Solitary fibrous tumor as a rare mesenchymal tumor can occur in a wide variety of body sites, including serosal membranes, liver, lung, and deep soft tissues; however, primary tumor arising in bone is rarely documented. Herein, we reported the MRI, bone scan, and FDG PET/CT findings of a primary spinal solitary fibrous tumor in a 39-year-old woman.

Clinical characteristics and prognosis of orbital solitary fibrous tumor in patients from a Chinese tertiary eye hospital

BACKGROUND

Solitary fibrous tumor (SFT) is predominant within the pleura but very rare in the orbit, which is why the diagnosis of orbital SFT poses challenges in clinical practice. Accordingly, an integrated approach that incorporates specific clinical features, histological, histopathological, and immunohistochemical (IHC) examinations, and molecular analyses is warranted.

AIM

To retrospectively explore the clinical and imaging characteristics, treatment, outcomes of a series of patients with orbital SFT.

METHODS

We conducted a retrospective review of a series of patients diagnosed with a histopathologic orbital SFT treated at a single institution. All data on demographics, clinical characteristics, imaging, treatment, postoperative histopathological and IHC examinations, and prognosis were collected.

RESULTS

In total, 13 patients were enrolled, 7 (53.8%) of whom had the tumor located in the superomedial quadrant of the orbit. Computed tomography revealed a solitary ovoid lesion in 10 (76.9%) patients and irregular lesion in 3 (23.1%) patients. Magnetic resonance imaging results were as follows: On T1 weighted images, 3 (23.1%) patients had hypointense mixed signals, whereas 10 (76.9%) patients showed isointense mixed signals; on T2 weighted images (T2WI), 3 (23.1%), 4 (30.8%), and 6 (46.2%) patients exhibited hypointense mixed, isointense mixed, and hyperintense signals, respectively. Notably, 12 (92.3%) patients showed significant enhancement, whereas there were patchy slightly enhanced areas in the tumor. All patients were treated by surgery. IHC analysis demonstrated that the tumor cells were immunoreactive for CD34, CD99, STAT-6, and vimentin in all patients. The lesions showed Ki-67 positivity < 5% in 1 (7.7) patient, 5%-10% in 10 (76.9%), and > 10% in 2 (15.4%). Two (15.4%) patients exhibited tumor recurrence.

CONCLUSION

The clinical manifestations and radiologic characteristics of orbital SFT are diverse and not specific. Accurate diagnosis and treatment require detailed radiological and histopathological/ IHC evaluation.

Arthroscopic Excision of Intra-articular AHRR-NCOA2- positive Angiofibroma of Soft Tissue of the Knee: A Case Report

BACKGROUND/AIM

Angiofibroma of soft tissue (AFST) is a rare benign soft-tissue tumor that most frequently occurs in the lower extremities. It has a characteristic genetic feature with a balanced chromosomal translocation t(5;8)(p15;q13), resulting in a fusion of aryl hydrocarbon receptor repressor (AHRR) and nuclear receptor coactivator 2 (NCOA2).

CASE REPORT

A 55-year-old woman presented with a 2-year history of left knee pain and recently noticed the development of a palpable mass. Magnetic resonance imaging exhibited a well-defined intra-articular mass with iso-signal intensity relative to skeletal muscle on T1-weighted sequences, heterogeneous high signal intensity on T2-weighted sequences and avid, diffuse enhancement on contrast-enhanced fat-suppressed T1-weighted sequences. After an ultrasound-guided core needle biopsy, the lesion was successfully treated by arthroscopically-assisted complete excision. Histologically, the tumor was composed of uniform bland spindle cells in a myxoid to collagenous stroma with a prominent vascular network. Immunohistochemically, the spindle cells were diffusely positive for CD163 and CD68 and focally positive for estrogen receptor. Moreover, AHRR-NCOA2 fusion gene was detected by reverse transcription-polymerase chain reaction. There has been no clinical evidence of local recurrence at 1-year follow-up.

CONCLUSION

This is the first report of the detection of an AHRR-NCOA2 gene fusion associated with intra-articular AFST. AFST should be included in the extended differential diagnosis of an intra-articular soft-tissue mass, particularly if the mass is vascular.

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

OBJECTIVE

Solitary fibrous tumors (SFTs) uncommonly occur in the musculoskeletal system, with limited available data on their MRI appearance. This study was performed to assess the MRI features of SFTs in the musculoskeletal system (MSK-SFTs).

MATERIALS AND METHODS

Pre-treatment MRI in 39 patients with pathologically proven SFTs in the trunk or extremities was evaluated. Patient demographics, clinical management and follow-up, and lesion histology were reviewed. MRI features including lesion location, size, morphology, signal characteristics, vascularity, and relationship to major neurovascular structures were assessed.

RESULTS

MSK-SFTs most frequently occurred in the lower extremity (23/39 cases, 59%), deep to fascia (29/39, 74%), and intermuscular (22/29, 76%) in location. The majority of deep lesions were located along a major neurovascular bundle (20/29, 69%). Lesions had well-defined margins (39/39, 100%), multilobulated contours (27/39, 69%), and measured mean 6.9 ± 2.8 cm. The majority of lesions had slightly hyperintense T1 signal (34/39, 87%) and heterogenous intermediate-to-high T2/STIR signal (28/38, 74%). A "pseudo-cerebriform" internal architectural pattern on fluid-sensitive sequences, with internal lobulations and low signal bands/septations, was observed in 63% (24/38) of lesions. Lesions commonly demonstrated prominent intra-lesional (30/39, 75%) and peripheral juxta-lesional flow voids. Local invasion of surrounding structures was uncommon (3/39, 8%). Mitotically active lesions (p = 0.02) and lesions with tumor necrosis (p < 0.01) were larger in size. Tumor necrosis was associated with T1 heterogeneity (p = 0.04). Distant metastasis occurred in 10% (4/39) of patients, all in mitotically active lesions pre-operatively considered at least at intermediate risk of metastasis.

CONCLUSION

MSK-SFTs commonly present as well-defined, hypervascular masses deep to fascia along major neurovascular bundles, with heterogeneous slightly hyperintense T1 signal, intermediate-to-high T2/STIR signal, and prominent macroscopic flow voids.

Extra-thoracic, extra-meningeal solitary fibrous tumours - A case series and service review

BACKGROUND

Solitary fibrous tumours (SFT) are a type of mesenchymal tumour. Whilst the majority of cases follow an indolent course a significant proportion of patients suffer metastases or disease recurrence post-surgical excision. Due to the unpredictable clinical course follow up duration and intensity remains contentious.

AIMS

We aimed to determine current outcomes of management of this tumour, apply and assess current risk recurrence models to determine if our standard of care could be improved upon.

METHODS AND PATIENTS

A prospective database of patients treated at a regional musculoskeletal oncology service was assessed. Only extra-pleural, extra-meningeal SFTs were included in the study. Surgical outcome and post-operative investigations were scrutinised and the Pasquali and Demicco recurrence risk models were applied and assessed.

RESULTS

From 2009 to 2019 12 patients were identified, 8 female and 4 males. Their age at diagnosis ranged from 21 to 76 years. 11 patients underwent surgery with curative intent and no patient suffered disease progression or recurrence, with a mean follow up time of 41 months. One patient presented with metastatic disease and was managed palliatively.

CONCLUSIONS

Following this review of our case series and utilising risk recurrence models published in the literature we have changed our follow up protocol. In new cases of SFT the Pasquali prognostic model, with the addition of the presence or absence of necrosis, will be utilised. If a patient has benign features on initial biopsy we propose to not perform staging. Furthermore, if biopsy and final pathology results remain concordant, with no concerning features, and the patient has undergone complete excision reduced intensity follow up could be considered.Level of evidence Level IV, retrospective case series.

A Rare Case of a Solitary Fibrous Tumor of the Spermatic Cord

Solitary fibrous tumors (SFTs) are rare mesenchymal tumors, originally identified in the pleura. Even though they have subsequently been described in several extrapleural sites, the incidence of SFTs in the spermatic cord is particularly rare. Here, we report a case of a 27-year-old male that presented with a 3-year history of left scrotal swelling. Computed tomography (CT) and ultrasound demonstrated multiple solid, hypoechoic well-circumscribed masses that were separate from the testis. Surgical excision of the mass led to pathologic diagnosis of a solitary fibrous tumor involving the spermatic cord. Solitary fibrous tumors, although rare, are an important differential diagnosis for urogenital tumors.

Extra-pleural solitary fibrous tumors: a review

Solitary fibrous tumor (SFT) is a rare mesenchymal ubiquitous tumor reported in the pleura and a wide variety of extrapleural locations, most frequently in the orbits and extremities.

Approximately 78–88% of SFTs are benign and 12–22% are malignant.

Although tumor characteristics are highly dependent on the location there are unifying features in MR imaging suggesting SFT: well-circumscribed, often lobulated nodular lesion, delayed contrast enhancement and the presence of fibrous contents which are hypointense on T1 and T2-weighted MRI imaging.

There are many SFT differential diagnosis, highly dependent to the tumor location. Due to its rarity the diagnosis of extrapleural SFTs may be challenging. Histopathologic analysis is always required to confirm the diagnosis and to allow the distinction between the benign and malignant forms.

We review pleural and extrapleural SFTs, presenting diagnostic clues, differential diagnosis and prognostic factors.

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

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

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.

Primary intrapulmonary solitary fibrous tumours

Due to the extreme rarity of primary intrapulmonary solitary fibrous tumours (SFTs), their clinical course, imaging characteristics, diagnosis, treatment and prognosis are poorly understood. The present study therefore assessed the diagnosis and management of primary intrapulmonary SFTs and systematically reviewed previously reported cases in the literature. A total of 5 patients who underwent resection for primary intrapulmonary SFTs were enrolled in the present study and their clinical course, tumour characteristics, management and survival were assessed in this retrospective study. Relevant studies regarding primary intrapulmonary SFTs were searched using PubMed and tumour characteristics, clinicopathologic features, therapeutic strategy and survival outcomes were reviewed. Of the 5 cases, all were males, with a mean age of 57.6 years (range, 37-68 years). All patients were asymptomatic and were identified incidentally on routine computed tomography examination. A total of 3 patients underwent thoracotomy and 2 patients underwent video-assisted thoracoscopic surgery. All tumours were completely resected. Postoperative haemorrhage occurred in 1 patient and he received surgical intervention for haemostasis. The average hospital stay was 15 (4-22) days, and no mortality occurred. The mean length of the postoperative follow-up was 37.6 (1-67) months. One patient was lost to follow-up, and 4 patients were asymptomatic. A total of 19 studies were identified from database searches. They included a total of 45 patients: Twenty-three males and 22 females (mean age, 59.4 years; range, 7-81 years). A total of 12 patients were asymptomatic, and pain and coughing were the major symptoms. Five, one, two, four, and 17 tumours occurred in the right upper lobe, right middle lobe, right lower lobe, left upper lobe and left lower lobe, respectively. A total of 39 patients underwent surgery, 1 patient underwent radiotherapy, and 1 patient underwent radiofrequency ablation. A total of 22 patients were followed up and the mean length of the postoperative follow-up was 48 (1-168) months. One patient was diagnosed with chest wall metastases, and 5 patients succumbed to mortality. To conclude, primary intrapulmonary SFTs are extremely rare and typically identified incidentally. The present findings indicated that the left lower lobe was the most common site location and complete surgical resection is a safe and effective treatment.

Rapid metastasis of mediastinal solitary fibrous tumor: Report a case

RATIONALE

Mediastinal solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms. Complete resection is considered as the effective treatment and the prognosis is quite good. Rapid metastasis after surgery is extremely rare.

PATIENT CONCERNS

In this case report we describe a 42-year-old man who present with a mediastinal malignant SFTs. Enhanced computed tomography of chest revealed a 4.5 × 4.0-cm mass in the anterior mediastinum.

DIAGNOSES

The tumor is composed of massive proliferation of atypical spindle cells. Immunohistochemical staining for cluster of differentiation (CD) 34, CD99, and vimentin were strongly positive.

INTERVENTIONS

Due to the possibility that the tumor was malignant, a standard median sternotomy was performed under general anesthesia. The mediastinal tumor and the affected part of the pericardium and right upper lobe of the lung were completely resected.

OUTCOMES

The patient underwent surgery and recovered uneventfully. After 2 months follow-up postoperation, there was recurrence in the chest wall and right middle lung. The patient refused any treatment and was dead after 2 months.

LESSONS

The present cases indicate that mediastinal SFTs should always be kept in mind for rapid metastasis. Once found, surgical intervention should be performed promptly. Due to the rapid metastasis, radiotherapy, and chemotherapy may be needed after surgery and long-term follow-up is required to monitor the metastasis of this type of tumor.

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.

The Value of MRI and Clinical Features in Differentiating Between Cellular and Fibrous Solitary Fibrous Tumors

OBJECTIVE

The purpose of this study is to evaluate the usefulness of MRI in differentiating between fibrous and cellular solitary fibrous tumors (SFTs).

MATERIALS AND METHODS

This retrospective study included 17 patients with histopathologically confirmed SFTs, including 10 patients with fibrous SFTs and seven patients with cellular SFTs. We evaluated the differences between fibrous and cellular SFTs with regard to clinical data and MRI findings, such as tumor margin definition, signal intensity, heterogeneity on T1- and T2-weighted images, presence of capsules, intratumoral cystic changes, flow signal void, perilesional edema, enhancement pattern on dynamic contrast-enhanced MRI (DCE-MRI), and mean apparent diffusion coefficient (ADC) values.

RESULTS

Statistically significant differences in fibrous and cellular SFTs were noted with respect to signal intensity on T2-weighted images (p = 0.044, by Fisher exact test) and enhancement patterns on DCE-MRI (p = 0.005, by Fisher exact test). Specifically, on T2-weighted images, five of the fibrous SFTs had high signal intensity, and the other five had signal isointensity, whereas all seven cellular SFTs had high signal intensity. On DCE-MRI, fibrous SFTs tended to show a gradual increase in enhancement, whereas cellular SFTs showed a rapid initial enhancement pattern. The mean (± SD) ADC value for cellular SFTs was 1.39 ± 0.35 × 10^-3 mm²/s, whereas that for fibrous SFTs was 1.37 ± 0.48 × 10^-3 mm²/s, with no statistically significant difference noted between the two (p = 0.755, by Fisher exact test).

CONCLUSION

Fibrous SFTs have nonspecific findings with regard to signal intensity on T2-weighted MR images and enhancement patterns on DCE-MRI, whereas cellular SFTs show high signal intensity on T2-weighted images and rapid initial enhancement on DCE-MRI.

Urethral Solitary Fibrous Tumor: A Rare Pathologic Diagnosis of a Periurethral Mass

Solitary fibrous tumors (SFTs) may occur at any site in the body. SFTs can only be conclusively diagnosed based on histopathologic and immunohistochemical characteristics of the tumor. The presence of SFTs in the abdomen and pelvis is extremely rare. To our knowledge no cases of urethral solitary fibrous tumor in the literature have been reported so far. We present a case of a solitary fibrous tumor arising from the urethra in a twenty-three-year-old female presenting with vaginal mass.

Solitary Fibrous Tumor of Central Nervous System: A Case Report

Solitary fibrous tumor (SFT) is a rare neoplasm of mesenchymal origin, especially in the central nervous system (CNS). Reported herein is a case of SFT of CNS in a 63-year-old female patient who had confused mentality, without other neurological deficit. The brain MRI showed an ovoid mass in the right frontal lobe. The tumor was surgically removed grossly and totally, and the pathologic diagnosis was SFT. At 55 months after the surgery, the tumor recurred at the primary site and at an adjacent area. A second operation was thus done, and the tumor was again surgically removed grossly and totally. The pathologic diagnosis was the same as the previous, but the Ki-67 index was elevated. Ten months later, two small recurring tumors in the right frontal skull base were found in the follow-up MRI. It was decided that radiation therapy be done, and MRI was done again 3 months later. In the follow-up MRI, the size of the recurring mass was found to have decreased, and the patient did not manifest any significant symptom. Follow-up will again be done 18 months after the second surgery.

A Solitary Fibrous Tumor (Cellular Form) of the Ankle

A solitary fibrous tumor (SFT) is a rare type of mesenchymal tumor composed of uniform spindle cells that is classically described as a patternless feature. SFT normally originates from the pleura, with an SFT originating from skin rarely reported. We report what we believe to be the first case of an SFT arising from the ankle. Our case was confirmed histopathologically with immunohistochemical staining.

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.

Prognosis of solitary fibrous tumors: a multicenter study

BACKGROUND

Solitary fibrous tumors (SFTs) are rare mesenchymal tumors, and data regarding outcome and prognostic factors are scarce. We report the outcome and analysis of prognostic factors of a retrospective multicenter cohort study for patients treated for SFTs.

METHODS

Retrospective analysis was performed of patients treated for SFTs between 1995 and 2012. Clinical and histopathological features were analyzed for prognostic value. Endpoints were set at local recurrence, metastasis formation, or death. Survival was analyzed using Kaplan-Meier and Cox proportional hazards analyses.

RESULTS

A total of 81 patients underwent surgical resection of a SFT with curative intent. During follow-up, 21 patients developed distant metastases, while 18 patients developed local recurrence. The 5-year overall survival was 84 %. The local recurrence rate and the metastasis rate at 5 years were 29 and 34 %, respectively. Of all factors analyzed, positive resection margin significantly correlated with local recurrence [hazard ratio (HR) 4.8; 95 % confidence interval (95 % CI) 1.5-14.9]. Tumor size >10 cm (HR 4.4; 95 % CI 1.7-11.5) and high mitosis rate (HR 3.3; 95 % CI 1.06-10.3) significantly correlated with higher incidence of metastases. The combination of tumors >10 cm and high mitosis rate significantly correlated with higher incidence of metastases (HR 4.8; 95 % CI 1.4-16.2) and showed a trend toward worse overall survival (HR 5.7; 95 % CI 0.95-34.7).

CONCLUSIONS

A substantial portion of patients with a SFT developed local recurrence or metastases. Local recurrence is significantly higher in patients with positive resection margins; metastasis frequency is significantly higher in patients with tumors >10 cm and tumors with a high mitosis rate.

Extrathoracic location and "borderline" histology are associated with recurrence of solitary fibrous tumors after surgical resection

BACKGROUND

Most solitary fibrous tumors (SFTs) are cured by complete resection, but many recurrent and metastatic SFTs do not respond to treatment and are fatal. Malignant histology, defined by England's pathologic criteria, is strongly associated with recurrence, but some benign SFTs still behave aggressively. Several studies have suggested that extrathoracic SFTs have a worse prognosis. We reviewed thoracic and extrathoracic SFTs from our institution to determine if extrathoracic location is associated with recurrence, independent of malignant histology.

METHODS

With IRB approval, we retrieved patient pathology reports from the Johns Hopkins Surgical Pathology database between 1991 and 2011 and included 83 SFT patients in our analysis. Patient history and outcomes were obtained from the medical record and primary care physicians. Predictors of recurrence were analyzed by univariate and multivariate analysis and survival determined by the Kaplan-Meier method.

RESULTS

Of the 83 patients, 59 had extrathoracic SFTs in neurologic (n = 24), extremity or head/neck (n = 13), or visceral/intraabdominal (n = 22) sites. A total of 74 SFTs were classified benign and 9 as malignant. Of the 14 recurrences, 13 occurred in extrathoracic SFTs; only 7 were classified as malignant. Multivariate analysis confirmed that malignant histology had the strongest association with recurrence, but extrathoracic location also independently predicted recurrence. A total of 20 benign SFTs possessed 1 or more of England's criteria but to an insufficient degree for malignant classification. These "borderline" SFTs were more likely to recur than benign SFTs without these features.

CONCLUSIONS

Extrathoracic and "borderline" SFTs with any of England's criteria have a higher risk of recurrence.

[Solitary fibrous tumor of the orbit: Possibly recurrent in the long-run]

Solitary fibrous tumor (SFT) is a rare etiology of progressive unilateral exophthalmia. The tumor is of mesenchymal origin and it is usually well defined. But recurrences can occur despite of complete surgical resection. Metastases have been observed. Tumors of the SFT spectrum are considered as benign or low-grade malignant. Histological features do not currently allow any prognosis. The most important prognostic factor is complete surgical resection. Craniofacial approaches provide a good view of the tumor extensions and orbital contents. Recurrent tumors must be surgically removed when possible. Complementary treatments have not proved effective. A very long-term follow-up is mandatory.

Radiology-pathology conference: malignant solitary fibrous tumor of the seminal vesicle

Mesenchymal neoplasms are rarely encountered in the seminal vesicle. Only four cases of the seminal vesicle solitary fibrous tumor have been reported in English literature, all of which were benign in nature. We are describing the clinicoradiological and pathological features of a locally aggressive malignant solitary fibrous tumor arising from the seminal vesicle, which posed the therapeutic challenge for the surgical management in a 52-year-old male patient. To our knowledge, this is the first reported case of the malignant solitary fibrous tumor arising from the seminal vesicle.