Presentation and Diagnosis - Most patients present in the 7th decade of life. - Females are affected more commonly than males (4:1 ratio). - The majority of tumors present in the upper lip. - Few tumors present in the palate or buccal tissue as a slowly enlarging mass. - Some tumors may show multifocality or multinodularity, which should not be confused with invasion or malignancy. - Tumors are usually small, with an average size of about 1.6 cm. - Histologically, there is a characteristic appearance to the tumor. - The tumor shows a canalicular pattern with cords and ribbons. - The connection points between opposing columnar cells within spaces create a 'string of pearls' appearance. - Small luminal squamous balls or morules are often present, along with a well-developed supporting tissue.

Treatment - Recurrences are more likely to represent multifocal tumors. - Conservative surgery is the treatment of choice.

References - Thompson LD, Bauer JL, Chiosea S, McHugh JB, Seethala RR, Miettinen M, Müller S (Jun 2015). Canalicular adenoma: a clinicopathologic and immunohistochemical analysis of 67 cases with a review of the literature. - Nelson JF, Jacoway JR (Jun 1973). Monomorphic adenoma (canalicular type). Report of 29 cases. - Suarez P, Hammond HL, Luna MA, Stimson PG (Aug 1998). Palatal canalicular adenoma: report of 12 cases and review of the literature. - Penner CR, Thompson LD (Mar 2005). Canalicular adenoma. - Ferreiro JA (Dec 1994). Immunohistochemical analysis of salivary gland canalicular adenoma.

Other - Canalicular adenoma must be differentiated from basal cell adenoma, pleomorphic adenoma, adenoid cystic carcinoma, and polymorphous adenocarcinoma. - Immunohistochemistry studies can be done to confirm the diagnosis. - Pathologists use pancytokeratin, S100 protein, and SOX10 markers for confirmation. - The tumor cells show a delicate GFAP reaction around the periphery. - Small calcifications or microliths may be present in a few cases.