Cytopathologic analysis of stroma-poor salivary gland epithelial/myoepithelial neoplasms on fine needle aspiration.

OBJECTIVE: Fine needle aspiration (FNA) diagnosis of salivary gland neoplasms with epithelial/myoepithelial cells but rare or no stroma is usually difficult. Our aim was to study the cytomorphology of this cohort of FNA cases and evaluate the clinical follow-up.

STUDY DESIGN: The diagnostic terminology for this group of aspirates was 'favor an epithelial/myoepithelial neoplasm of the salivary gland'. The cytologic smears of 32 such cases were retrieved and showed cellular smears with bland-appearing or mildly atypical epithelial and myoepithelial cells without typical chondromyxoid stroma seen in pleomorphic adenoma (PA).

RESULTS: Twenty of the 32 cases had histologic follow-up. Ten of these 20 cases were PAs, including 8 cellular PAs. Two cases were basal cell adenomas, 1 case myoepithelioma and 1 case benign adenoma, not otherwise specified. Among the 6 malignant tumors on surgical resections, there were 3 epithelial-myoepithelial carcinomas, 1 myoepithelial carcinoma, 1 basal cell adenocarcinoma and 1 adenoid cystic carcinoma.

CONCLUSIONS: Although 14 of the 20 (70%) cases were benign neoplasms, a substantial amount of cases (30%) were malignant salivary gland neoplasms. The generic diagnostic terminology of 'epithelial/myoepithelial neoplasm of the salivary gland' and appropriate clinical follow-up are recommended for these cases.