Multiple canalicular adenomas: a case report and review of the literature.

The canalicular adenoma is an uncommon, benign salivary gland tumor that most frequently occurs in the upper lip. Rarely, it manifests itself clinically and histologically as a multifocal lesion, a feature not generally seen with other intraoral salivary gland tumors. Here we report a case of canalicular adenoma that manifested itself with 13 clinically discrete tumor masses involving the upper lip and anterior buccal mucosa. In addition to the clinical nodules, there were microscopic foci of tumor cells in the adjacent normal-appearing salivary gland tissue surrounding the tumors. This article also reviews previously reported multifocal canalicular adenomas and discusses their features, emphasizing differences in the reported growth patterns of this unusual tumor.