Fibrous and fibrohistiocytic neoplasms: an update.

Important advances in fibroblastic and fibrohistiocytic tumors relevant to dermatologists and dermatopathologists include (1) recognition that myxofibrosarcoma is a distinct entity that frequently arises in skin; (2) CD10 is sensitive but not specific atypical fibroxanthoma; (3) neurothekeomas lacking S100 expression are probably fibrohistiocytic/fibroblastic tumors, whereas S100+ myxoid variants are better classified as nerve sheath myxomas; (4) the recognition of a primary cutaneous variant of solitary fibrous tumor; (5) thelimitations of b-catenin immunohistochemistry in desmoid tumors; and (6) the prognostic utility of clinical and histopathologic variables in dermatofibrosarcoma protuberans, and the effects of imatinib mesylate therapy.