An unusual presentation of Merkel cell carcinoma: a case report.

Merkel cell carcinoma (MCC) is a rare, aggressive carcinoma that usually arises in sun-exposed regions. MCC is a primary neuroendocrine tumor that arises in the skin. This report describes an unusual case of MCC on the buttocks that was treated with excision, radiation and chemotherapy. Physicians should consider MCC as a differential diagnosis when encountering a rapidly growing, painless lesion. Early diagnosis and treatment may improve patient survival rates.