Cytological features of intraoral tumour

Canalicular adenoma is an uncommon, benign salivary gland tumour, which occurs almost exclusively in the intraoral salivary glands. The upper lip is the most common site, accounting for about 80% of all cases, followed by the buccal mucosa and palate. It is commonly diagnosed in patients after 60 years of age and appears as a painless, slowly growing submucosal mass, smaller than 2 cm in dimension. The overlying mucosa may be normal, erythematous or have a bluish tint, similar to a mucocele. Histologically, a canalicular adenoma is composed of cords of columnar and cuboidal cells with occasionally small cystic spaces in between. Commonly, there is also a connective tissue capsule. Based on ultrastructural and histochemical findings, some authors have suggested that the canalicular adenoma could possibly be of excretory duct origin, although intercalated duct origin has also been mentioned. Only a few detailed studies about the cytopathological features of the canalicular adenoma were previously published in the English-language literature. One study using fine needle aspiration biopsy (FNAB) described canaliculi and papillae lined by a layer of columnar epithelium consisting of columnar cells with round, basal nuclei and clear cytoplasm. Here, we describe in detail the clinical, cytological and histological features of two intraoral canalicular adenomas and emphasize the cytological differential diagnosis. Case reports