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 superfi cial 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.

Cytological diagnosis of a rare case of primary Merkel cell carcinoma of the parotid gland

“…Primary MCC represents approximately 1% of salivary gland malignancies and occurs primarily in the parotid gland with a reported 5‐year survival rate of 56%‐64%. Explanations for the presence of MCC in such atypical locations have included theories of malignant transformation and neuroendocrine migration . We report here a rare case of primary MCC of the parotid gland diagnosed cytologically with the support of morphology and immunocytochemistry without prior history of the disease.…”

Primary retroperitoneal Merkel cell carcinoma: Case report and literature review

“…It is estimated that 97.6% of MCC cases occur in the skin and 0.4% occur in other locations [23] . MCC has been reported in the lips and oral cavity [24] , parotid gland [25] , and lymph nodes [26] , [27] , [28] , [29] . Only 2% of all cases present without a primary site [20] .…”

Merkel Cell Carcinoma of the Hand

“…Although rare, MCC has also been found infrequently on the penis, vulva, and in the parotid gland. 5,10,14 Macroscopically, MCC presents most commonly as an asymptomatic nodular red/pink lesion <2 cm in size, which demonstrates rapid growth of the tumor within weeks to months. 12 Microscopically, it is characterized by small and round to oval cells disposed as either a discohesive population or as cohesive clusters of cells.…”