Immunohistochemical profile of canalicular adenoma of the upper lip: a case report.

Canalicular adenoma is an uncommon benign salivary gland neoplasm that has a marked predilection for occurrence in the upper lip. It is composed of columnar cells arranged in branching and interconnecting cords of single or double cell thick rows. This tumor has an excellent prognosis after conservative surgical treatment in all locations. In the present report we describe, using immunohistochemistry, the expression of cytokeratins (CK), S-100 protein and EMA in a canalicular adenoma that arose in the upper lip of a 55-year-old female. Cells of the canalicular adenoma showed an immunohistochemical profile that indicates an excretory duct origin: most of these cells positively expressed AE1/AE3 cytokeratins and S100 protein. A comparison of the immunohistochemical features of canalicular adenoma with other salivary gland neoplasms that share similar histological features is discussed.