Extraparotid Warthin Tumors Imitating Metastasis of Oral Cancers.

 Extraparotid Warthin tumor (WT) is a very rare entity, especially when synchronous with oral cancer (OC).  The present study presents a case series of extraparotid WTs detected in the surgical specimen of patients treated for OC.  From 2007 to 2016, 336 patients were operated for OC in our institution. Neck dissection was performed in 306 patients.  In the 306 patients operated for OC whose necks were dissected, unexpected WTs were observed in 4 surgical neck specimens. In 3 cases, extraparotid WTs were responsible for tumor, node, metastasis (TNM) overstaging before surgery.  Extraparotid WTs may be discovered during neck dissection in ∼ 1% of OC patients, and they may mimic neck metastasis, especially in positron-emission tomography/computed tomography (PET/CT) imaging.