[Clear-cell acanthoma].

The basis for this review forms a series of 20 new cases of clear cell acanthomas and the literature on this subject. The clinical and histopathological characteristics of this not too rare skin tumor and newer histochemical and electron microscopical findings are discussed. Particular attention will be paid to the question of the position of the clear cell acanthomas within the group of intraepidermal acanthomas and the "clear-celled" tumors of the skin. Presently, the clear cell acanthoma can be classified as a benign epidermal tumor of unknown etiology. It is assumed that the clear cell acanthoma arises through a special disturbance of the differentiation of keratinocytes.