20 cases of adenoacanthoma, diagnosed out of a total of 1,100 cutaneous epitheliomas were studied. All cases were facial, with actinic elastose. In 11 of the 20 cases, the appearance was that of a tumor with a central crater. Histopathologically, the characteristic appearance of adenoacanthoma (tubular and alveolar formations with acantholytic and dyskeratotic cells) was associated with structures of squamous cell epithelioma. In 4 of the 20 cases, there were glandular tumoral manifestations derived from the sweat glands. Clinically, they have a local malignancy, and a relative radioresistance. In no case was there gangliar metastasis; but in 2 cases, there was extension along the perineural lymphatics. In 4 cases of acantholytic keratosis, an indication of transition toward adenoacanthoma was seen. This supports the hypothesis that this form of keratosis is the departure-point for adenoacanthoma.