Malignant fibrous histiocytoma of the glans penis.

A case of malignant fibrous histiocytoma of the penis in a 56-year-old Hispanic man is described. The tumor was composed of a proliferation of atypical spindle cells showing the characteristic storiform growth pattern. Immunohistochemical stains were positive for vimentin and alpha-1-antichymotrypsin and negative for keratin, desmin, and S-100 protein antibodies. The unusual location of this tumor in our patient highlights the ubiquitous distribution of this malignant neoplasm. The clinical and histologic differential diagnosis of this lesion is discussed.