Evidence-based management of primary and localized Merkel cell carcinoma: a review

Merkel cell carcinoma is a rare and often lethal cutaneous neuroendocrine malignancy with a tendency for early and frequent locoregional and distant metastasis and relapses. It is a tumor of the elderly and immunosuppressed, which most often appears on sun-exposed areas of the body. There is growing interest in characterization of the disease and the best approach to its management. Despite the lack of prospective randomized clinical trials, treatment is evolving.

To provide an updated review of the most current and relevant data concerning the surgical (± radiological) management of Merkel cell carcinoma, including the role of Mohs micrographic surgery.

Using relevant MeSH terms, we performed a review of the literature on the above subjects from 1981 to 2011.

For primary tumors without evidence of organ metastases, surgical excision should be the primary therapy. Owing to the high rate of local metastases, a safety margin of at least 2 cm should be considered. In situations where small, localized tumors and/or special locations necessitate a smaller safety margin, compensation by complete histological examination of the excision margins and perhaps adjuvant radiation therapy should be undertaken. The literature states that benefits of Mohs micrographic surgery (over wide local excision) include tissue conservation and identification of tumors that may require extremely wide excision margins. The majority of data to date supports the use of Mohs surgery in the treatment of Merkel cell carcinoma.