title: Reactive fibrohistiocytic proliferation simulating fibrous histiocytoma.
abstract: A pelvic nodule was excised at the time of reexploration of the abdomen in a 32-year-old women who had previously had a malignant germ cell tumor with a mixed histologic pattern of the right ovary. The 3-cm firm lesion from the right vaginal apex was composed predominantly of spindle cells with a prominent storiform pattern. Some findings, such as the presence of foamy histiocytes and a focal foreign body reaction with polarizable material, were atypical for a lesion otherwise quite acceptable histologically as a fibrous histiocytoma. Ultrastructural findings also tended to support the reactive rather than neoplastic nature of this mass. There is a similarity to the silica reaction described by Weiss and co-workers (Cancer 42:2738-2743, 1978).
mesh_terms: D000328:Adult; D002455:Cell Division; D003937:Diagnosis, Differential; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005260:Female; D006644:Histiocytes / Q000166:cytology*; D018219:Histiocytoma, Benign Fibrous / Q000175:diagnosis* / Q000648:ultrastructure; D006801:Humans; D010051:Ovarian Neoplasms / Q000473:pathology / Q000648:ultrastructure; D010063:Ovum / Q000473:pathology