Synchronous Warthin tumor and papillary oncocytic cystadenoma in the ipsilateral parotid gland: an unreported association.

The occurrence of ipsilateral, synchronous, primary salivary gland tumors of different histological type is rare. In this report, we present the case of a 52-year-old male, established smoker, who showed simultaneously two different benign tumors in the right parotid gland. The patient complained of swelling below the angle of the mandible. Ultrasonography and computed tomography imaging revealed one mass of about 2.8 cm in the right gland. Besides, one small nodule in the left parotid gland was observed. The cytological diagnosis of the right gland was benign tumor, type IVa of the Milan system, consistent with Warthin tumor (WT). The clinical diagnosis was bilateral parotid WT. The histopathological (HP) study of the surgical specimen revealed a WT in combination with a papillary oncocytic cystadenoma (POC) in the right parotid. To our knowledge, this combination of tumors has not been previously reported. In our case, the association of tumors was not detected by imaging or fine-needle aspiration cytology (FNAC). WT and POC are difficult to distinguish by FNAC because their epithelial component is very similar. POC can resemble WT without lymphoid stroma, but the totality of HP features allows the differentiation of both processes. These tumors can be related to a common causal determinant and should not be considered as a result of chance. Both tumors follow favorable courses and are curable by surgical resection.