[Merkel cell carcinoma. Study of five cases].

Merkel cell carcinoma (MCC) is a rare malignant skin tumor of neuroendocrine origin with a poor prognosis and rapid progression. It is usually an erythematous nodule on the face, and is associated with other skin neoplasms. Its histology shows a large mass of small cells containing oval nuclei with powdery chromatin in the dermis. These cells are positive for neurospecific enolase, chromogranin, synaptophysin and cytokeratins AE1/AE3. We present five patients (3 males and 2 females, aged 58 to 89 years) seen at our hospital in the last three years for MCC. Their treatment and evolution were tracked, and many of the aspects indicated were seen. MCC must be kept in mind in the differential diagnosis, as early detection along with aggressive treatment significantly improve the patients survival rate. Close follow up is necessary because of the high recurrence rates. The development of a response protocol in order to better manage this disease would be desirable.