Merkle cell carcinoma report of a case and possible role for adjuvant radiotherapy.

A case of neuroendocrine (Merkle cell) carcinoma of the skin is described. This uncommon tumor occurred in a 76-year-old female and presented as a small exophytic nodule on the right anterior chest wall. Following primary excision, it was thought to be a basal cell carcinoma. The diagnosis of Merkle cell carcinoma was established only after the tumor had recurred locally and involved ipsilateral axillary lymph nodes. Although local control was achieved with surgery and radiotherapy, the patient died of probable hepatic metastases 18 months after presentation. The Merkle cell tumor is an undifferentiated small cell carcinoma originating in the skin and has distinct ultrastructural characteristics that help to differentiate it from other small cell tumors. The clinicopathologic characteristics of these potentially aggressive neoplasms are reviewed, and treatment is briefly discussed.