Making a cytologic diagnosis of basal cell adenocarcinoma (BCAC) of the salivary gland is difficult due to the similarity of its morphologic features to other benign and malignant tumors of the salivary glands. Morphometric analysis revealed that the average minimum diameter of the nuclei of BCAC was significantly wider than that of basal cell adenoma (BCA). BCAC was associated with a higher nuclear circularity compared with BCA. Our case report shows that roundness of the nuclei, formation of a palisading pattern, and presence of a basement membrane-like material in fine-needle aspiration specimens could lead to a specific diagnosis of BCAC.
