Fine-needle aspiration cytology of monomorphic adenomas.

The diagnostic accuracy of fine-needle aspiration of salivary gland lesions is now widely accepted. The cytologic appearance of two rare monomorphic variants of pleomorphic adenomas is described. The trabecular-tubular adenoma consisted of a trabecular arrangement of uniform small cells with scant basophilic cytoplasm and round nuclei. No mucoid spheres were present. The canalicular adenoma also had a distinctive cytologic appearance consisting of papillae and interconnected canaliculi lined by a layer of columnar epithelium. Monomorphic adenomas have unique morphologic appearances that can be recognized in fine-needle aspiration cytology. Preoperative diagnosis can greatly aid the surgeon in the planning of definitive surgical excision of salivary gland neoplasms.