Primary Merkel cell carcinoma of the parotid gland.

ABSTRACT

Primary Merkel cell carcinoma (MCC) is a neuroendocrine tumor that typically affects older whites. It usually originates in the dermis, but in rare instances it has arisen in other primary sites, including the oral mucosa and the parotid gland. Explanations for the presence of MCC in these atypical locations have included theories of malignant transformation and neuroendocrine migration. We describe the case of a 35-year-old white woman who had an MCC in the parotid gland and no evidence of any other primary cutaneous lesion. A left superficial parotidectomy with facial nerve preservation was performed, and a histologic diagnosis of MCC was made. Positron-emission tomography was negative for other lesions, and postoperative radiation therapy was administered for local control. To the best of our knowledge, this is only the sixth case of a primary MCC of the parotid gland to be reported in the English-language literature; of these 6 patients, ours was by far the youngest. Otolaryngologists should be familiar with this rare but potentially fatal neoplasm.