Desmoplastic trichoepithelioma.

Fifty examples of a distinctive clinicopathologic entity occurred in 49 patients who ranged in age from 8 to 70 (median 46) years. Forty-nine tumors were on the face, mainly the cheek, chin and forehead; most were present one to five years, and 85% of the patients were female. The growths varied in size from 3 to 8 mm; many were hard and annular, with a raised border and depressed nonulcerated center. Histologically, narrow strands of basaloid cells and epidermoid cyts infiltrated a fibrotic stroma. This tumor, which we have named desmoplastic trichoepithelioma, must be differentiated histologically from morphealike basal cell carcinoma, desmoplastic cutaneous metastasis, and certain benign adnexal neoplasms.