Mucoepidermoid Carcinoma of the Parotid Gland Mimicking Pleomorphic Adenoma on Cytology: A Case Report

Salivary gland tumors most commonly involve the parotid gland. Among all the tumors, 80% are benign and of all the benign tumors 80% originate from the parotid gland. The pleomorphic adenoma is the most common benign tumor whereas the mucoepidermoid carcinoma is the most prevalent malignant tumor. Mucoepidermoid carcinoma is a diagnostic challenge on FNAC with a high false negative rate. A 17-year-old female presented with slow-growing painless swelling below the right ear for two years. The history and clinical examination appeared to be benign parotid swelling. The further investigation proceeded and fine needle aspiration cytology was performed. A case of the parotid lump which has shown the pleomorphic adenoma of the parotid gland on cytology. Surgical resection was done and a post-operative specimen of the parotid gland showed mucoepidermoid carcinoma on histopathology. FNAC is not always reliable in the case of mucoepidermoid carcinoma of the parotid gland, especially in the low-grade type. The confirmatory diagnosis can be made only after the histopathological examination.