Synchronous Bilateral Multifocal Warthin's Tumor Mimicking Primary Malignancy on F-FDG Whole Body PET/CT in a Case of Metastatic Cervical Lymph Nodes from Unknown Primary Malignancy.

Warthin's tumor is a benign and frequently encountered salivary gland neoplasm. Bilaterality and multifocality are rare in Warthin's tumor. Synchronous cervical lymph nodal metastasis with unknown primary in a case of Warthin's tumor can raise a suspicion of primary malignancy of the parotid gland. We present a case of bilateral multifocal Warthin's tumor with synchronous squamous cell carcinoma metastasis to the cervical lymph node. F-fluorodeoxyglucose whole body positron emission tomography/computed tomography imaging showed hypermetabolic bilateral multifocal parotid lesions and metastatic cervical lymph node with unknown primary malignancy.