["Pagetoid reticulosis" (Woringer and Kolopp disease). A disease of the Merkel cell (author's transl)].

A case of Woringer and Kolopp disease "Pagetoid reticulosis" is described. Clinical features include a ring of a target pattern of erythemato-squamous infiltrated skin lesion. The characteristic histological aspect of dense epidermal infiltrate by abnormal cells with a spared dermis has been observed. Ultrastructural findings include cytoplasmic granules with a found electron dense core and close relationship to neurites, two features of the Merkel cell of human normal epidermis. By comparing our patients with the already reported cases of Woringer and Kolopp disease it seems likely that this is a unique disease with no relationship with cutaneous lymphoma but which is defined by a Merkel cell proliferation.