Sclerosing Mucoepidermoid Carcinoma of the Parotid Gland: A Case Report

ABSTRACT

Sclerosing mucoepidermoid carcinoma (SMEC) is a very rare tumor of the salivary gland. There have been eight cases of SMEC reported in the medical literature; this is the first reported case in Korea. A 51-year-old woman presented with a right infra-auricular mass that she had for 3 years. We performed superficial parotidectomy. Grossly, the resected parotid gland showed a well-circumscribed firm mass. Histologically, the tumor consisted of central solid or ductal tumor nests within a dense fibrous stroma surrounded by peripheral lymphoid infiltration. The tumor nests were composed of squamous, intermediate and mucin-secreting cells. However, the tumor cells lacked mitosis and nuclear anaplasia. The lymphoid cells were mostly composed of lymphocytes and plasma cells with occasional eosinophils and neutrophils. Immunohistochemically, the tumor cells were positive for high- and low- molecular weight cytokeratins, cytokeratin 7, p16INK4A, Bcl-2 and cyclin D1. The patient also underwent radiation therapy. We report here on a case of SMEC of the parotid gland along with the immunohistochemical characteristics, and we review the relevant literature.