Adenocarcinoma Arising in Warthin's Tumor of the Parotid Gland: A Rare Case Report.

Warthin's tumor is the second most common tumor of parotid gland consisting of lymphoid and epithelial components. It is seen in the elderly population and is more common in males. It is a benign tumor and has strong association with smoking. Malignant transformation is very rare in Warthin's tumor and can involve both the lymphoid, as well as epithelial components. Here we present a rare case of malignant transformation in Warthin's tumor in a female patient. She presented with an infra-auricular swelling on right side for 1 year with rapid increase in size of the swelling since last 3 months. Imaging studies showed possibility of a benign parotid tumor. Fine needle aspiration cytology showed features of Warthin's tumor. Histopathology and Immunohistochemistry confirmed the diagnosis of malignant transformation of Warthin's tumor to adenocarcinoma.