Solitary fibrous tumor: Histologic and immunohistochemical spectrum of benign variants presenting at different sites
ABSTRACT Twenty-nine tumors (from 26 patients, including two with recurrent disease) diagnosed as solitary fibrous tumor (SFT) of the pleura (n = 23), mediastinum (n = 4), abdominal cavity (n = 1), and parotid gland (n = 1) were studied immunohistochemically. Three histologically malignant tumors showed areas of high cellularity and mitotic activity (more than 4 mitoses/10 high-power fields) with features resembling malignant fibrous histiocytoma, malignant hemangiopericytoma, or fibrosarcoma, together with areas typical of benign solitary fibrous tumor. Formaldehyde-fixed, paraffin-embedded tissues and avidin-biotin-complex immunostaining were used. All of the tumors showed vimentin positivity and did not stain for cytokeratin, glial fibrillary acidic protein, or muscle cell markers, except for focal desmin reactivity in seven tumors, mostly seen in frozen sections, and focal keratin reactivity in one histologically malignant tumor. The neoplastic cells were positive for CD34 and negative for CD31; these patterns also were seen in the three histologically malignant cases. In nine of the cases acetone-fixed frozen sections showed variable focal positivity for neurofilament proteins of 68 kd. We conclude that SFT is a neoplasm of fibroblasts/primitive mesenchymal cells with features of multidirectional differentiation. We also report the finding of a novel site for SFT, the parotid gland.
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- "1323% of cases   . High cellularity, increased mitotic activity (more than 4 mitoses per 10 high-power fields), pleomorphism and haemorrhage are the factors favouring malignancy  . "
ABSTRACT: Solitary fibrous tumours are rare spindle cell tumours that generally arise from the pleura but on rare occasions arise in other locations such as the head and neck region, stomach and retroperitoneum. Very few reports exist on the imaging findings of these tumours in extra pleural sites such as the mesentery. We report the computed tomography (CT) imaging findings of a rare case of solitary fibrous tumour in a 68-year-old man who presented with a slowly enlarging painless pelvic mass. CT scan showed a well-defined, multilobulated, highly vascular pelvic mass with dense calcifications and central hypoatteunating areas arising from the mesentery.Cancer Imaging 10/2009; 9(1):67-9. DOI:10.1102/1470-7330.2009.0014 · 1.29 Impact Factor
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- "Localized fibrous tumors of the pleura (LFTP) represent a rarely encountered clinical entity            . After several decades of controversies, it is nowadays recognized that they originate from mesenchimal cells of submesothelial tissue of the pleura   . It is recognized that surgery represents the treatment of choice of these tumors    . "
ABSTRACT: The aim of this paper is to study clinical characteristics, surgical treatment and outcome of patients with solitary fibrous tumor of the pleura operated in our institutions in a 20-year period. Clinical records of all patients operated for solitary fibrous tumors of the pleura between 1981 and 2000 were reviewed retrospectively. Tumors were classified as malignant in the presence of at least one of the following criteria: (1) high mitotic activity; (2) high cellularity with crowding and overlapping of nuclei; (3) presence of necrosis; (4) pleomorphism; otherwise they were considered as benign. Sixty patients (mean age 55 years) were operated in this period. None had asbestos exposure. Symptoms were present in 31 cases. Surgical approaches included thoracotomy (n=53), video-assisted thoracoscopy (n=6), and median sternotomy (n=1). Tumors originated from visceral pleura in 48 cases, from parietal, mediastinal or diaphragmatic pleura in seven, two and three cases, respectively; their mean diameter was 8.5 cm. Tumors could be resected with their implantation basis in 49 patients. In the remaining 11, extended resections were performed, including lung parenchyma (lobectomy, n=4, pneumonectomy, n=2), osteomuscular chest wall structures (n=2), diaphragm (n=2), and pericardium (n=1). Two postoperative deaths (due to myocardial infarction and pulmonary embolism, respectively) occurred. Tumors were pathologically benign in 38 cases and malignant in 22 cases. Mean follow-up was 88 months. Resection was complete in all the patients with benign tumors and no recurrence occurred. Resection was considered as complete in 21/22 malignant tumors. Local recurrence was observed in two cases. Both could be successfully managed by iterative exeresis (no extended resection had been initially performed). Metastatic disease (responsible for patient's death) was observed following the only incomplete resection. Actuarial 5- and 10-year survival rates were 97% for benign tumors and 89% for malignant ones. Surgical resection provided cure in all the patients with benign tumors. As insufficiency of exeresis is associated with all recurrences in malignant tumors, completeness of resection is in our experience the best prognostic factor in these forms.European Journal of Cardio-Thoracic Surgery 07/2002; 21(6):1087-93. DOI:10.1016/S1010-7940(02)00099-4 · 2.81 Impact Factor
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ABSTRACT: Our goal is to describe the MR findings in benign localized fibrous tumors of the pleura. Chest radiographs, CT scans, and MR images of four patients with localized benign fibrous tumors of the pleura were retrospectively reviewed and correlated with the pathologic findings. Tumors ranged from 4 to 18 cm in their largest diameter. Three tumors were located in the diaphragmatic region, and one was within the left major fissure. All tumors were round to ovoid, pedunculated, and well delineated. On T1-weighted SE MR images, tumors showed low signal intensity. All tumors had heterogeneous but predominantly low signal intensity on proton-density-weighted images and lower signal intensity on T2-weighted images. Localized benign fibrous tumors of the pleura were characterized by low signal intensity on all MR sequences that is explained by high collagen content within the tumors' stroma and should suggest the diagnosis preoperatively.Journal of Computer Assisted Tomography 01/1997; 21(1):115-20. DOI:10.1097/00004728-199701000-00023 · 1.60 Impact Factor