Mast cells in the aspiration cytology differential diagnosis of adenolymphoma.

Review was undertaken of 20 cases of adenolymphoma (Warthin's tumor) of the salivary glands diagnosed by fine needle aspiration (FNA). Smears of the aspirates from 16 of the 20 cases (80%) contained mast cells associated with monolayered sheets of oncocytes. Aspiration smears from control cases showed cells in significantly fewer instances: 10% of the cases of mucoepidermoid carcinoma, 5% of the cases of pleomorphic adenoma and none of the cases of acinic-cell tumor, squamous-cell carcinoma and branchial cysts. Mast cells in association with oncocytes thus should be considered supportive evidence of an FNA diagnosis of adenolymphoma.