Left panel shows a low power view of this characteristically cystic lesion with central amorphous fluid surrounded by papillary formations and an intense lymphoid infiltrate. The right panel demonstrates the typical bilayered epithelium of dense eosinophilic columnar cells. The dense eosinophilia qualifies these cells as oncocytes, which are cells with cytoplasm packed with mitochondria. These tumors are commonly accompanied by squamous or mucinous metaplasia, which should not be interpreted as malignant (mucoepidermoid carcinoma).
