RESUMEN
Cystadenoma rarely arises in the parotid gland. It grows slowly without pain. Histopathologically, it is subdivided into papillary cystadenoma and mucinous cystadenoma. Mucinous cystadenoma arising from the salivary gland is a very rare benign tumor. A 25-year-old female patient visited our hospital with a left infra-auricular mass. Computed tomography scan showed a 3.1x2.3 cm size heterogeneous lesion with an irregular margin in the left parotid gland. Sono guided gun biopsy was performed to reveal fibrous tissue with atypical epithelial cell with mucin. Suspecting mucoepidermoid carcinoma, partial parotidectomy was performed for treatment and diagnosis. Histopathologic exam revealed mucinous cystadenoma. Cystadenoma of salivary gland has no distinct clinical feature, and is difficult to differentiate clinically from other salivary gland tumors as well as its malignancy. Thus, the possibility of malignancy must be considered for differential diagnosis.