Project description:Solitary fibrous tumors (SFTs) are uncommon neoplasms of mesenchymal origin that were first described as primary spindle-cell tumors of the pleura in 1931. Since then, infrequent case reports of extrapleural SFTs have been described including various subsites within the head and neck. Based on a review of the literature and a description of the endoscopic treatment of three patients with SFTs of the nasal cavity and ethmoid sinuses, the challenges associated with the management of sinonasal SFTs are discussed. Successful endoscopic resection was performed at a tertiary referral rhinology practice within a university center in three cases of sinonasal SFTs with no evidence of recurrence at 26, 35, and 49 months following resection. Summarized are the common presenting symptoms, appropriate diagnostic workup, and indicative computed tomography and magnetic resonance imaging appearance of SFTs. Further discussed are the challenge associated with accurate histological and immunohistochemical diagnosis, the difficulty in assessing the aggressiveness and malignant potential of these lesions, and the appropriate treatment and follow-up duration that these neoplasms require.
Project description:Solitary fibrous tumors (SFTs) can occur in several locations outside the pleura, but rarely in the sinonasal tract, and particularly not in the nasopharynx. Herein, we describe an unusual case of giant cell-rich SFT (GCRSFT) occurring in the nasopharynx. A 64-year-old man experienced dizziness and headache for more than 10 years with no obvious cause. Computed tomography (CT) scan showed a 3.9 cm × 2 cm tumor on the posterior lateral wall of the left nasopharynx, and angiography revealed a hypervascular tumor fed by branches of the left carotid artery. Hence, preoperative embolization was performed, and then the tumor was endoscopically resected. The symptoms were relieved after the resection, and postoperative head CT and video laryngoscopy showed that the tumor was completely resected. We next characterized the specific pathological characteristics of the resected tumor. Histologically, the tumor was characterized by varying cellular proliferation of cytologically bland spindle cells within a collagenous stroma, with prominent interspersed branching vessels. Mitotic activity was low (2/50HPF), and there was no evidence of pleomorphism or tumor necrosis. Moreover, multinucleated giant cells with deep nuclear staining and distributed in pseudovascular spaces were found within the tumor. We ruled out the possibility that our case was giant cell fibroblastoma (GCF) by immunohistochemical analysis, showing that the tumor cells were positive for CD34, CD99, STAT6, and BCL-2, and that the Ki-67 labeling index was 3%, indicating that our case was SFT and not GCF. The patient's condition is generally good after a 14-month follow-up. This report serves to broaden the morphologic spectrum of GCRSFT and will help clinicians and pathologists better understand this entity to prevent misdiagnosis.
Project description:Solitary fibrous tumor (SFT) is a rare, soft tissue neoplasm that rarely presents in breast tissue, with only 27 previously reported cases. To our knowledge, only one case of malignant SFT has been reported in the English literature. A 75-year-old Caucasian woman presented to our institution with a 3-month history of a palpable left breast mass. No other symptoms, including nipple discharge or skin changes, were noted. She underwent 3 previous biopsies for right breast masses, all of which were benign, with no evidence of spindle cell neoplasm, atypical hyperplasia, or malignancy. Microscopic examination of the mass demonstrated a classic area of SFT with areas of high-grade anaplastic component. In these areas, the tumor showed atypical epithelioid cells arranged in hypercellular sheets with diminished branching vasculature, nuclear pleomorphism, and increased mitotic count (up to 9/10 high-power fields). This case represents the second case of malignant SFT in the breast.
Project description:Solitary fibrous tumors (SFTs) are NAB2-STAT6 fusion-associated neoplasms. There are several subtypes of NAB2-STAT6 fusions, but their clinical significances are still unclear. Moreover, the mechanisms of malignant progression are also poorly understood. In this study, using 91 SFT cases, we examined whether fusion variants are associated with clinicopathological parameters and also investigated the molecular mechanism of malignant transformation using whole-exome sequencing. We detected variant 1b (NAB2ex4-STAT6ex2) in 51/91 (56%) cases and variants 2a/2b (NAB2ex6-STAT6ex16/17) in 17/91 (19%) cases. The NAB2-STAT6 fusion variant types were significantly associated with their primary site (P?<?0.001). In addition, a TERT promoter mutation was detected in 7/73 (10%) cases, and it showed a significant association with malignant SFTs (P?=?0.003). To identify molecular changes during malignant progression, we selected an index patient to obtain parallel tissue samples from the primary and metastatic tumors. In the metastatic tissue, 10 unique molecular alterations, including those in TP53 and APAF1, were detected. In vitro functional experiments showed that APAF1 depletion increased the tumor potency of cells expressing NAB2-STAT6 fusion protein under treatment with staurosporine. We found that TP53 immunopositivity (P?=?0.006) and loss of APAF1 immunoreactivity (P <?0.001) were significantly associated with malignant SFTs. Our study suggests that dysfunction of TP53 and APAF1 leads to impaired apoptotic function, and eventually contributes toward malignant SFT transformation. KEY MESSAGES: We firstly found that the TERT promoter mutation was strongly associated with malignant SFTs (P?=?0.003) and the representative 1b (NAB2ex4-STAT6ex2) or 2a (NAB2ex6-STAT6ex16) fusion variants similarly contribute to tumorigenicity. We also found that TP53 immunopositivity (P?=?0.006) and loss of APAF1 immunoreactivity (P?<?0.001) were significantly associated with malignant SFTs. Our study suggests that dysfunction of TP53 and APAF1 leads to impaired apoptotic function, and eventually contributes toward malignant SFT transformation.
Project description:Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms found areas lining the pleura. First reported in 1931, there have been a total of 55 cases of SFTs of the kidney worldwide. In most cases, SFTs presents with hematuria, flank pain, and enlarging abdominal mass. In this case, we report a case of a patient who underwent a radical nephrectomy to remove an SFTs of the kidney with compression of the vena cava. This case further expands upon the importance of diagnosing and assessing the aggressive clinical behavior of SFTs during treatment and follow up.
Project description:Solitary fibrous tumors are uncommon soft tissue tumors initially reported only in the pleura but, in recent years, they have been described at many extra pleural sites, such as mediastinum. The treatment of choice is the extensive surgical resection that is curative for most benign lesions.We present the case of solitary fibrous tumor of the anterior mediastinum in obese patient (BMI: 34.3) undergoing complete surgical resection by robotic-assisted thoracoscopic surgery with da Vinci® Surgical System.Robotic-assisted thoracoscopic surgery with da Vinci® Surgical System is an interesting option for obese patient, at higher risk for deep sternal wound infection.
Project description:A solitary fibrous tumor (SFT) is a rare mesenchymal tumor. Ex situ hepatectomy and liver autotransplantation are novel methods for the treatment of complicated liver tumors, for example, those involving vascular structures, including the inferior vena cava, which are unresectable by conventional approaches. The present study describes a rare case of a massive hepatic SFT in a 32-year-old female who underwent ex situ hepatectomy and liver autotransplantation to achieve a radical resection. The surgery was without complications. Post-operative histopathological and immunohistochemical examinations revealed an SFT of the liver. The patient was discharged 29 days after the surgery with fully recovered liver function. The routine check-up 3 months after surgery indicated normal liver function and no evidence of recurrence. Additionally, an exhaustive review of available literature was performed to provide a complete overview of the current status of SFTs. In summary, the present study found that ex situ hepatectomy and liver autotransplantation are suitable surgical techniques for treating a giant SFT, as well as other liver neoplasms that are considered unresectable by conventional surgery.
Project description:The localized form of giant cell tumor of the tendon sheath is one of the most common soft tissue tumors of the foot and ankle region. It is characteristically a benign, sharply localized peritendinous fibrous mass in the synovial or tendinous spaces. The purpose of this Technical Note is to present the technical details of endoscopic resection of giant cell tumor of the extensor tendon of the foot with preservation of the tendon. It is indicated in the localized form of giant cell tumor of the extensor tendon at the foot dorsum. It is contraindicated in cases with a diffuse giant cell tumor, a giant cell tumor of the extensor tendon at the phalangeal level, or involvement of the flexor tendon.
Project description:Solitary fibrous tumors (SFTs) are unusual mesenchymal tumors that were first described as primary spindle-cell neoplasms of the pleura. These tumors have been described in many other locations, including the urogenital system, orbit, mediastinum, and upper respiratory tract. Twenty-two cases of an SFT of the paranasal sinuses and nasal cavity have been reported, but none described a malignant SFT extending through the anterior skull base. A 70-year-old man had a 6-month history of unilateral left-sided epiphora and nasal obstruction. Computed tomography and magnetic resonance imaging showed a large left-sided nasal cavity mass with extension into the left extraconal orbit and intracranial extension through the left cribriform plate and ethmoid roof. The patient underwent preoperative embolization of the internal maxillary artery and a subsequent anterior craniofacial resection via a midfacial degloving approach and a left anterior craniotomy. Histopathological analysis of the specimen was consistent with a malignant SFT.
Project description:Solitary fibrous tumor is a mesenchymal neoplasm exhibiting a broad spectrum of biological behavior and harboring the NAB2-STAT6 fusion. Clinicopathologic parameters are currently used in risk-prediction models for solitary fibrous tumor, but the molecular determinants of malignancy in solitary fibrous tumors remain unknown. We proposed that the activation of telomere maintenance pathways confers a perpetual malignant phenotype to these tumors. Therefore, we investigated telomerase reverse transcriptase (TERT) reactivation induced by promoter mutations as a potential molecular mechanism for aggressive clinical behavior in solitary fibrous tumor. The retrospective study included tumor samples from 94 patients with solitary fibrous tumor (31 thoracic and 63 extra-thoracic). Follow-up information was available for 68 patients (median, 46 months). TERT promoter mutation analysis was performed by PCR and Sanger sequencing, and TERT mRNA expression was assessed by real-time quantitative reverse transcription PCR. Patients were stratified into clinicopathologic subgroups (high-risk (n=20), moderate-risk (n=28), and low-risk (n=46)) according to the risk-stratification model proposed by Demicco et al. TERT promoter mutations were identified in 26 of 94 (28%) solitary fibrous tumors: -124C>T in 23 tumors (88%), -124C>A in 1 tumor (4%), and -146C>T in 2 tumors (8%). Real-time quantitative reverse transcription PCR revealed that TERT mRNA expression was higher in all solitary fibrous tumors with the mutant TERT promoter than those with the wild-type TERT promoter. TERT promoter mutations were strongly associated with high-risk clinicopathologic characteristics and outcome. An adverse event (relapse, death) occurred in 16 of 68 (24%) patients, 12 with solitary fibrous tumors with TERT promoter mutations and 4 with the wild-type TERT promoter. TERT promoter mutations were strongly associated with older age (P=0.006), larger tumor size (P=0.000002), higher risk classifications (P=2.9 × 10-9), and a worse event-free survival (P=0.0082). Thus, TERT promoter mutations in solitary fibrous tumor influence gene expression and are associated with adverse patient outcome. Integrating TERT promoter mutational status with existing multivariable risk-prediction models might improve risk prediction in patients with solitary fibrous tumor.