A rare case of a papillary cystadenoma extending from the lower lip to the buccal mucosa of a 79-year-old female is presented. The tumor consisted of a single cyst with multiple papillary projections into its cystic space. It appeared to have potentially malignant characteristics because the cellular atypia of this tumor had apparently increased histologically in surgical specimens obtained two times from the same patient.
When encountered, papillary cystadenoma should be treated by radical removal, and the patient should be carefully followed up similar to other patients with malignant tumors.
