[Merkel-cell tumor].

A Merkel cell tumor of the preauricular region in a seventy-seven years old woman is described. Histological, electronmicroscopic and tissular hormonal studies, were made. From the pathological point of view, a nodular and trabecular pattern of oval or elongated cells with poor basophilic cytoplasma is characteristic. Large nuclei with irregular, oval prominent nucleoli are also present. Electron microscopy shows oval and polygonal cells of irregular nuclei with one or multiple prominent nucleoli. In the cytoplasm of these cells, microfilaments and dense core granules with clear halo are found. The tissular hormonal determinations were normal. Two years after the surgical treatment, the patient remains asymptomatic.