[Crystalloids in salivary gland pleomorphic adenoma]

We examined crystalloids in salivary gland pleomorphic adenomas. The crystalloids were detected in 4 of 34 pleomorphic adenomas (11.7%). In three cases they were found in the minor salivary gland and in one case in the major salivary gland. Light microscopy revealed that all the crystalloids were in parenchyma. They were composed of eosinphilic structure and radially arranged clusters of needle-shape fibers. The central parts sometimes contained clear space. They were usually closely surrounded by neoplastic myoepithelial cells. All 4 cases containing crystalloids were million reaction-negative and positive to van Gieson, Mallory and Reticulin Silver Impregnation stains. Therefore all the crystalloids in our 4 cases were considered as collagen-rich.