[Woringer and Kolopp's disease (author's transl)].

Woringer and Kolopp's disease is a rare skin disease. Erythemato-squamous, slightly infiltrated lesions with round-shaped islets of normal skin are the clinical hall-marks of the disease. The histological picture is highly specific: a dense epidermal infiltrate disrupts the stratum spinosum, contrasting with a spared dermis. Three different aspects of the disease have been reported: a localized benign type as in Woringer and Kolopp's patient; a disseminated lethal type without visceral involvement and without preexisting lesions, and a disseminated lethal type in which lesions appear on erythematous patches clinically and histologically similar to "parapsoriasis en plaques". It is the opinion of the authors that the third type is not Woringer and Kolopp's disease but an extremely epidermotropic variant of mycosis fungoides. The two other types seem to be variants of the same disease. Several hypotheses about the nature of that disorder are discussed. Most authors think that Woringer and Kolopp's disease is a cutaneous lymphoma because of clinical, histological and ultrastructural similarities with mycosis fungoides. We are presenting evidence favoring the hypothesis of a Merkel cell proliferative disease.