Dopa-positive cells and melanin in basal cell epithelioma (BCE).

In 47 out of 61 bce's, melanocytes were detectable with the aid of Dopa-reaction. In 24 of these cases, the percentage of tumour cells was less 5%, and in 23 it was more. The melanocytes preferred the periphery of the epithelial tumour formations. Only when the proportion of melanocytes exceeded 5% were they also to be found in the central parts of the tumours. Generally the melanocytes were more numerous in the upper parts of tumours, next to the epidermis. Our findings strengthen the opinion, that bce is a tumour of the primary hair germ.