[Merkel cell carcinoma. Report of 4 cases].

We report four cases of Merkel cell carcinoma, a rare cutaneous neuroendocrine neoplasm with a high malignant potential. The first patient is a 90 years old male presenting with a tumor in the left superior eyelid. Surgical excision was the only treatment and seven months later, a local and regional tumoral relapse caused the death of this patient. The second patient is a 83 years old female with a tumor in her left ear. She was treated surgically and with radiotherapy, being free of disease after five years of follow up. The third patient is a 45 years old male with a tumor in the left forearm. Treatment was surgical excision of the primary tumor and axillary lymph nodes. He received post operative radiotherapy and is free of disease after three years of follow up. The last case is a 76 years old male, who was subjected only to an excisional biopsy of a lesion located in the left knee. He had a tumor relapse with inguinal and crural lymph node involvement that caused his death 12 months later.