Merkel cell carcinoma - Review of 22 cases with surgical, pathologic, and therapeutic considerations

BACKGROUND. Merkel cell carcinoma is a primary small blue cell tumor of the skin with a proclivity to metastasize. Surgery and radiation therapy have defined roles in the primary treatment of Merkel cell carcinoma. Systemic c hemotherapy can produce good response rates but does not have a primary rol e in the management of nondisseminated Merkel cell carcinoma patients. METHODS. Twenty-two patients were identified over the last 10 years in a re trospective analysis of tumor registries from the 6 hospitals of the Scripp sHealth facilities. Hospital and clinic charts as well as pathology specime ns were reviewed. RESULTS. Eight patients underwent Mohs' surgery with permanent tissue techn ique. None of these patients had a subsequent local recurrence. Six patient s received adjuvant radiation therapy, only one of whom developed a disease recurrence within a radiation port. Systemic chemotherapy was given to sev en patients. One patient did not accept further treatment after a punch bio psy. CONCLUSIONS. Merkel cell carcinoma is an aggressive primary neoplasm of the skin, the histologic diagnosis of which can be difficult. Mohs' surgical t echnique combined with radiation therapy provides excellent local control. Systemic treatment is associated with high response rates, but to the autho rs' knowledge durable responses are uncommon. Cancer 2000;88:1842-51. (C) 2 000 American Cancer Society.