Clear Cell Basal Cell Epithelioma

Abstract

A 36-year-old woman was seen at our hospital because of a slowly enlarging lesion of 2 years’ duration. Examination revealed a nodule of the size of a little finger’s head on the occipital region. Histologically, a circumscribed, non-encapsulated tumor composed of basophilic cells with peripheral palisading was located in the dermis. However, some of the tumor cells exhibited either a pale granular or clear cytoplasm. In these cells, many vacuoles of different sizes were found. While the cytoplasm of the clear cells showed negative for Sudan III, PAS produced a sparse positive staining. Neither S100 protein, carcinoembryonic antigen, nor lysozyme was detected. Based on these observations, our case was diagnosed as a clear cell basal cell epithelioma.