[Merkel cell carcinoma: follow-up of 10 patients. Current diagnosis and therapy].

Merkel cell carcinoma (MCC) is a rare neoplasm of the skin predominantly found on the head and extremities. Clinically MCC presents as a rapidly growing red or violaceous, dome-shaped, solitary tumor. The clinical and histological diagnosis of MCC remains difficult. Distinction from poorly differentiated small cell primary tumors or metastasis requires immunohistochemical analysis and-if available-electron-microscopic studies. We report on the follow-up of 10 patients with MCC treated in the past 6 years at our department. In nine patients the tumors were completely removable; in one patient with a large primary tumor of the upper lip no histologically proven complete excision could be performed. After a median follow-up of 42 months, local recurrence or lymph node involvement was observed in three patients. Two patients died following disseminated metastases, one elderly patient due to cardiac insufficiency. Our observations demonstrate that MCC is a potentially aggressive cutaneous tumor. Adequate primary surgical and adjuvant therapy as well as careful follow-up are mandatory.