Extracellular material in adenoid cystic carcinoma of the salivary glands: a comparative cytological study with other salivary myoepithelial tumors.

The objective of this study was to clarify extracellular materials (ECMs) in adenoid cystic carcinoma (AdCC) and compare these to those found in other salivary gland tumors with myoepithelial differentiation. The ECM was examined with Papanicolaou, May-Grünwald-Giemsa (MGG), and alcian blue stain at pH 2.5. The ECM in AdCC was classified into three types according to their staining patterns: clear, hyalinized, and membrane type. The incidence of clear-type globule material with magenta on MGG was low in other salivary gland tumors with myoepithelial differentiation. The ECM was identified in other salivary gland tumors with myoepithelial differentiation. However, AdCC has the greatest variety of ECM. These findings are useful to understand the character of AdCC and differential diagnosis of the other salivary gland tumors with myoepithelial differentiation. Copyright 2004 Wiley-Liss, Inc.