Palatal canalicular adenoma: report of 12 cases and review of the literature.

Canalicular adenoma is the second most common type of adenoma of the oral region and arises almost exclusively in the upper lip. Other locations include the buccal mucosa, the palate, and the parotid gland. We report 12 cases of canalicular adenoma that arose in the palates of nine women and three men between the ages of 42 and 76 years. The tumor presented as a nonulcerated (eight patients) or ulcerated (four patients) lesion, usually at the junction of the hard and soft palates. Two tumors were misdiagnosed: one as adenoid cystic carcinoma and the other as low-grade adenocarcinoma. Both patients had had partial maxillectomy; the patient diagnosed with adenoid cystic carcinoma also received radiotherapy. One patient reported having had an adenoma removed from the palate 10 years previous to presentation; thus, the tumor was classified as a recurrence. Evidence of tumor metastasis was absent in all cases during the follow-up period, which ranged from 1 to 25 years. Eleven patients are alive and disease free; one died of other causes. Canalicular adenoma does not commonly occur in the palate. This tumor has an excellent prognosis after conservative surgical treatment in all locations. Pathologists should be aware of the occurrence of this neoplasm in the palatal region and of its histopathology so they can distinguish it from malignant tumors of the salivary gland.