Oncocytic adenocarcinoma of the lacrimal sac: report of a case with paranasal sinus and orbital extension.

A 92-year-old man has had multiple recurrent oncocytic tumors involving the right paranasal sinuses and orbit. A benign oncocytoma that arose from the right lacrimal sac was initially diagnosed at age 80 years. The tumor recurred at 3 and 7 years after initial resection. There was greater histologic atypia in the first recurrent tumor, which extended into the right paranasal sinuses. The second recurrence had zones on oncocytic adenocarcinoma exhibiting prominent nuclear atypia and mitotic activity; this tumor massively invaded the right paranasal sinuses and orbit. We describe the clinical and pathologic features of this rare case.