Basal-Cell Epithelioma on Nevus

Abstract

This is the report of a rare1disease, nevus syringocystadenomatosus papilliferus (Werther), complicated by a superimposed superficial type of basal-cell epithelioma. It is Lever's2belief that basal-cell epitheliomas occur only in areas where primary epithelial germ structures (hair, sebaceous or apocrine glands) are found. They may be present in the same lesion with nevus sebaceous, syringocystadenoma papilliferus, sebaceous epithelioma, or trichoepithelioma. It is also his thought that basal-cell epitheliomas are not carcinomas, not derived from basal cells, but are nevoid tumors (hamartomas) originating from arrested embryonal primary epithelial germ cells. The proposition, concerning the nonmalignant nature of this tumor, is based on the fact that they probably never metastasize as such, and the reported metastesizing basal-cell epitheliomas, although rare, could represent a wrong diagnosis.3 Tumors showing an intermediate stage of differentiation between basal-cell epithelioma and any one of the benign epitheliomas as mentioned do occur and have been reported.2