Salivary oncocytic cystadenoma with intraluminal crystalloids: a case report with review of the literature.

Oncocytic cystadenoma is a rare benign tumor of major salivary glands that in rare occasions may present histologically with intraluminal crystalloids. We report a case of 53-year-old man with a progressively enlarging lump in the left submandibular region. Ultrasound examination revealed a cystic mass with an intraluminal fluid collection. The tumor was surgically removed. Histologic examination yielded a diagnosis of oncocytic cystadenoma with a high concentration of intraluminal crystalloids. The microscopic features of the crystalloids were compatible with nontyrosine (alpha-amylase) crystalloids. When compared with previously published cases in the literature, this is the first report of oncocytic cystadenoma with intraluminal crystalloids arising in the submandibular gland, and the second reported case of the nontyrosine type of crystalloids occurring in association with this tumor. The nontyrosine crystalloids may be highly characteristic to salivary gland tumors with oncocytic differentiation.