Classification and differential diagnosis of clear and basal cell tumors of the salivary glands.

Several cell types of the salivary glands and their neoplasms may have a clear cytoplasm. Classification of their cytological features is made possible with special stainings, immunohistochemistry, and electron microscopy. Clear cell tumors of the salivary glands are usually formed by one distinctive cytological type. A new but distinct and very rare salivary gland neoplasm is the hyalinizing clear cell carcinoma, which should be differentiated from other clear cell salivary tumors. Salivary gland tumors with predominance of a basal cell component are basal cell adenoma, basal cell adenocarcinoma, and the solid type of adenoid cystic carcinoma. The differential diagnosis of clear cell and basal cell tumors is of great importance for the prognosis and treatment of these tumors.