Project description:Solitary fibrous tumors of the pleura (SFTPs) are rare neoplasms of mesenchymal origin most commonly arising in the pleura and have a benign biological behavior in the majority of cases. Most patients with SFTPs are asymptomatic; however, symptoms are mostly related to the mass effect within the thoracic cavity. Chest computed tomography (CT) scanning is the radiographic test of choice, but findings lack specificity. Surgical resection is the treatment of choice for most patients. Long-term survival after resection of benign SFTPs is excellent. In this case series, we present two females, one presented with shortness of breath (SOB) and nonproductive cough and the other one was referred because of abnormal x-ray findings. The histological as well as the immunohistochemical examination revealed the mass to be a solitary fibrous tumor of the pleura.
Project description:Solitary fibrous tumors (SFT) is a rare type of soft tissue tumors and there have been only a few reported cases of SFTs at the perineum region. We report a SFT below the pubic bone in a 35-year-old male causing compression on his corpus spongiosum. The patient underwent en bloc tumor resection with preservation of spermatic vessels and the bladder neck. Pathological evaluation and immunohistochemistry (IHC) staining with CD34(+), CD99(+), STAT6(+), S100(-) and Desmin(-) confirmed the diagnosis of SFT. Surgery plays a key role in treatment strategies and pathological examination with IHC is important in the diagnosis of SFTs.
Project description:BackgroundWe report two resected cases of solitary fibrous tumors (SFT) that were accidentally found in the pelvic cavity.Case presentationCase 1 was a 54-year-old male. A colonoscopy for the examination of intestinal polyps revealed an extramural tumor in the right anterior wall of the low rectum. A preoperative MRI showed a well-demarcated T1 low and T2 mixed intensity extramural tumor (53 × 36 mm) located right lateral to the low rectum and behind the seminal vesicle. Laparoscopic surgery was successful for tumor extirpation. Immunohistochemical examination of the specimen revealed STAT6 (+) and CD34 (+) cells, a Ki67 positivity of 7-8%, a mitotic index of 4-5/50 HPF, and a diagnosis of SFT. There was no recurrence 29 months after surgery. Using RT-PCR and sequencing, we detected the NAB2-STAT6 fusion gene but the locus of genomic inversion was not detected. Case 2 was a 43-year-old male that received conservative treatment for appendicitis. A CT scan accidentally revealed a tumor of 40 mm of length in the left obturator area. A MRI revealed a well-demarcated T1 and T2 high intensity tumor. The patient underwent surgical biopsy. Immunohistochemical examination of the biopsy revealed STAT6 (+) and CD34 (+) cells, Ki67 positive cells < 1%, and a diagnosis of SFT. We could not detect the NAB2-STAT6 fusion gene in the extirpated tumor.ConclusionsTwo cases of pelvic SFT were diagnosed by immunohistochemical examination, RT-PCR and sequencing and successfully resected by laparoscopic surgery.
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:BackgroundSolitary fibrous tumor (SFT) is a rare mesenchymal malignancy. Although surgery is potentially curative, the local relapse risk is high after marginal resections. Given the lack of prospective clinical trial data, the objective of the current study was to better define the role of perioperative radiotherapy (RT) in various SFT presentations by location.MethodsThis was retrospective study performed across 7 sarcoma centers. Clinical information was retrieved from all adult patients with extrameningeal, primary, localized SFT who were treated between 1990 and 2018 with surgery alone (S) compared with those who also received perioperative RT (S+RT). Differences in treatment characteristics between subgroups were tested using analysis of variance statistics and propensity score matching. Local control and overall survival rates were calculated from the start of treatment until progression or death from any cause.ResultsOf all 549 patients, 428 (78%) underwent S, and 121 (22%) underwent S+RT. The median follow-up was 52 months. After correction for mitotic count and surgical margins, S+RT was significantly associated with a lower risk of local progression (hazard ratio, 0.19: P = .029), an observation further confirmed by propensity score matching (P = .012); however, this association did not translate into an overall survival benefit.ConclusionsThe results from this retrospective study investigating perioperative RT in patients with primary extrameningeal SFT suggest that combining RT with surgery in the management of this patient population is significantly associated with a reduced risk of local failures, especially in patients who have less favorable resection margins and in those who have tumors with a high mitotic count.
Project description:Solitary Fibrous Tumors (SFT) is a relatively rare occupying lesion, which often originated from the pleura and has been reported in a series of reports. However, there are few reports on retroperitoneal SFT. To better understand its biological behavior, clinical diagnosis and follow-up strategy, this case studied the manifestations, diagnosis and treatment of retroperitoneal SFT in a 57-year-old woman, and reviewed the relevant literature.
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.
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.