Diagnostic Difficulties in Fine Needle Aspiration of Benign Salivary Glandular Lesions

BACKGROUND The diagnostic accuracy of fine needle aspiration cytology (FNAC) of salivary lesions is relatively high, but cytologic interpretation might be confusing if the sample is lacking typical cytologic features. METHODS There were 77 cases of benign salivary lesions, consisting of pleomorphic adenoma (PA) in 61 cases, Warthin's tumor (WT) in 12 cases, and other benign lesions in 4 cases. The causes of the discrepancies between the FNAC and the histologic diagnoses were evaluated. RESULTS Major discrepancies were noted in 4 of the 61 PA cases, and in 1 of 12 WT cases. The causes of the major discrepancies were a mislabeled site in 1 PA and 1 WT case, and an interpretation error in 3 PA cases. Minor discrepancies were more common in the WT cases (7 of 12 cases) than in the PA cases (11 of 61 cases). The causes of the minor discrepancies were a mislabeled site in 1 PA and 1 WT case, an inadequate sample in 7 PA and 2 WT cases, a lack of typical cytomorphology in 2 PA and 2 WT cases, and an interpretation error in 1 PA and 2 WT cases. CONCLUSIONS To increase the diagnostic accuracy in the benign salivary lesions, recognition of both characteristic and less typical cytomorphology is needed.