Mucus Retention Cyst of Parotid Gland: A Rare Case Report

Abstract

Case ReportSwellings of the major salivary gland commonly lead to the differential diagnosis which includes benign and malignant tumors that are frequently associated with cystic degeneration or entirely cystic in nature. Mucus retention cysts are true cysts that rarely involve the major salivary glands. 6% to 9% of the major salivary gland swellings present as a cystic lesion and only 2-5 % of them are non-neoplastic in nature. A 21 year-old female patient presented with swelling in right parotid region for last one and half years. CECT of the parotid region show a well-defined oval fluid density lesion measuring 2.4cmx1.9cmx3.4cm in the superficial lobe of the right parotid gland with extension into the deep lobe of the parotid gland. On FNAC, 7ml creamish fluid was aspirated which on microcopy showed foamy histiocytes in a mucoid background. A diagnosis of benign cystic lesion was made cytologically. The patient underwent right subtotal parotidectomy. Gross examination revealed a globular soft tissue piece with attached fatty tissue piece measuring 5x4x3cm. On cut section a cystic cavity identified measuring 3.5x2.7x2.0cm. Cyst cavity was filled with thick mucoid material. Microscopic examination revealed a cyst lined by cuboidal and partially by pseudostratified columnar epithelium. Interspersed mucus cells also present in lining epithelium. Lumen of cyst showed proteinaceous material. Compressed salivary gland parenchyma also seen at the periphery. No cellular atypia was seen. A diagnosis of Mucus retention cyst of right parotid gland was rendered histopathologically.