Cytodiagnosis of acinic cell carcinoma. Ultrastructural study of material obtained by fine needle aspiration biopsy.

The material obtained by fine needle aspiration biopsy from a metastatic acinic cell carcinoma was evaluated by light and electron microscopy. A preliminary diagnosis of acinic cell carcinoma established by light microscopy was confirmed by electron microscopic study. Glandular arrangement of cancerous cells and the presence of a specific type of secretory granules in their cytoplasm were the most characteristic ultrastructural features of the acinic cell carcinoma.