An ultrastructural study of ghost cells appearing in calcifying odontogenic cyst.

Abstract

A calcifying odontogenic cyst that occurred in the mandible of a 40-year-old man was ultrastructurally examined with special reference to the appearance of the peculiar ghost cells (GCs) that are characteristic of this cyst. The following results were obtained: The GCs were derived from odontogenic epithelial cells following the increase in the number and width of tonofilamentous bundles in the cytoplasm, and were formed by the disruption and disappearance of nucleus and plasma membrane of the epithelial cells. This process of GCs formation closely resembled the process of hard keratinization of the nail and the hair cortex. Many needle-like or radial structural calcifications were detected in the cytoplasm of the GCs. It was suggested that the yellowish-brown granules microscopically observed in the GCs were ultrastructurally lipid droplets.