Fine‐needle aspiration cytology of basal cell adenoma of the parotid gland: Characteristic cytological features and diagnostic pitfalls

Abstract

We retrospectively studied the cytological features of aspiration cytology in 12 cases of basal cell adenoma (BCA) and 5 cases mistakenly diagnosed as BCA. On macroscopic findings, the 12 cases of BCA included 7 cases of solid type and 5 cases of cystic type. The characteristic cytological features of solid type BCA were three‐dimensional clusters in 71%, sharp‐angle small clusters in 86%, basement membrane‐ like material in 71%, and cell crush in 86%. In contrast, 3 of the 5 cystic type BCA cases showed inadequate cellular components or no basaloid tumor cells, and the cytological diagnosis of BCA could not be determined. In the 5 cases misdiagnosed as BCA, there were 2 cases of pleomorphic adenoma, 2 cases of benign lymphoepithelial cyst, and 1 case of basal cell adenocarcinoma. Accurate differential cytological diagnosis of BCA is relatively easy to determine the solid type BCA, but is more difficult for cystic type BCA. Diagn. Cytopathol. 2007;35:85–90.