Primary cutaneous vs. parotid mucoepidermoid carcinoma of the scalp: A case report

Primary cutaneous mucoepidermoid carcinoma remains a rare occurrence. This is the first report of a case of primary cutaneous mucoepidermoid carcinoma originating on the scalp and subsequently metastasizing to the parotid gland. The patient was a 53-year-old female who presented with a purple mass on her scalp since 5 months prior to examination. Histopathology revealed nests and islands of atypical epithelioid cells with pleomorphism, medium to prominent nucleoli, and scattered mucin deposition highlighting with a mucicarmine stain. The atypical cells demonstrated intravascular involvement. These findings were compatible with metastatic adenocarcinoma. Later, fine needle aspiration of the patient's parotid lesion revealed malignant cells from a poorly differentiated carcinoma that appeared similar to the patient's previously excised scalp lesion. In addition to summarizing this patient's presentation, clinical course, and management, we discuss the diagnostic challenges posed by this atypical presentation. Primary cutaneous mucoepidermoid carcinoma should be considered in the differential diagnosis of patients presenting with a scalp mass. Moreover, patients with primary cutaneous mucoepidermoid carcinoma originating on the scalp should be evaluated for possible metastases.