Solitary fibrous tumour: clinicopathological, immunohistochemical, and ultrastructural analysis of 12 cases arising in soft tissues, nasal cavity and nasopharynx, urinary bladder and prostate

摘要: The clinicopathological features of 12 extraserosal solitary fibrous tumours (SFT) are described. age the patients ranged from 18 to 72 years (mean: 48.2 years; median: 54 years); 5 were female patients. Seven lesions arose in soft tissue (5 perifascial, and 1 each subcutaneous intramuscular tissues). They situated groin (2 cases) neck, right buttock, left scapula, upper arm, anterior abdominal wall (1 case each). One polypoid lesion was seen nasal cavity nasopharynx; 2 neoplasms urinary bladder located prostate periprostatic tissue. Nine excised; patient wide excision performed patients, transurethral resection. Limited follow-up 3 cases revealed a benign clinical course. size 1.7 cm 20.0 5.4 cm; 3.5 cm). Histologically, well circumscribed composed cytologically bland spindle cells arranged without an obvious pattern; focally storiform or fascicular growth patterns seen. Tumour separated by thick bands collagen demonstrating foci keloid-like hyalinization. Prominent vascularity showing haemangiopericytoma-like vascular pattern vessels with thick, hyalinized vessel walls all cases. Increased mitotic activity noted (4-6 mitoses 10 high-power fields); other showed fewer than figures highpower fields. Immunohistochemically, tested stained positively for vimentin, CD34 CD99, focal myofibroblastic differentiation. Two examined ultrastructurally fibroblastic phenotype; pinocytic vesicles microfilaments identified. SFT represents distinct neoplasm that should be included differential diagnosis spindle-cell tissue, nasopharynx, bladder, prostate. Strict diagnostic criteria necessary avoid overdiagnosis confusion more aggressive these locations.