Fibrous papules. A light microscopic and immunohistochemical study.

Abstract

Thirty-six cases of fibrous papules of the face and nose were studied by light microscopy and by immunohistochemistry. Positive staining with antibodies to vimentin and negative staining with antibodies to S-100 protein, alpha 1-antichymotrypsin, and factor VIII-RAG of the spindle, stellate, and multinucleated cells observed in the dermis support a fibroblastic line of differentiation. Fibrous papules of the nose and face are a distinctive clinicopathologic entity that most probably represents an inflammatory rather than a neoplastic process, sharing some histologic features of angiofibromas (angiofibrosis) and perifollicular fibromas (perifollicular fibrosis).