Merkel cell carcinoma: a review of management

Merkel cell carcinoma is an uncommon but aggressive primary cutaneous neuroendocrine (small cell) carcinoma. The head and neck is a frequent site (50-60%) for presentation. The optimal treatment of patients with Merkel cell carcinoma remains debated with recent evidence adding support for a multimodality approach. Despite this the outcome for patients with unfavourable disease remains poor and in many series 25-50% of patients die as a direct result of Merkel cell carcinoma.

Wide excision (2-3 cm) of the primary lesion has been recommended, although achieving this is often impossible within the functional and cosmetic constraints of the head and neck. The well-documented responsiveness of this disease to radiotherapy and chemotherapy has strengthened the case for less radical surgery. Current best practice, as presented in recent publications, would support adjuvant wide-field radiotherapy, delivered after wide excision with negative microscopic margins, as best practice. The role of platinum-based chemotherapy remains under investigation.

Most patients with a Merkel cell carcinoma should be recommended wide-field adjuvant radiotherapy to encompass the primary site, in-transit tissue and first echelon lymph nodes following surgery. The benefit of adding chemotherapy is currently unproven and should be considered on an individual basis.