Merkel cell carcinoma.

Merkel cell carcinoma is a rare cutaneous neoplasm most commonly affecting the head and neck of elderly white patients. Even with treatment, Merkel cell carcinoma has a strong propensity toward local recurrence, lymphatic spread, and distant metastasis. Because of its rarity and the subsequent lack of well-controlled clinical trials, no single standard of care exists for the treatment of this aggressive tumor. In our institution, primary lesions are excised with wide margins or by Mohs' micrographic surgery. After local removal, the excision site is treated locally with external radiation therapy. Sentinel lymph node mapping and biopsy are performed. Patients with tumor within a sentinel lymph node undergo lymph node dissection and radiation to the lymphatic basin. Adjuvant chemotherapy is offered to high-risk patients with local disease and to patients with metastases. Patients with distant metastases are treated with a combination of salvage chemotherapy and radiation therapy.