Hyaline bodies of odontogenic cysts: histological, histochemical and electron microscopic studies.

Hyaline bodies of odontogenic cyst were examined by histological, histochemical and electron microscopic observations. They were seen only in odontogenic cysts and their prevalence was 6.9% in 576 cases of the cysts. They occurred most frequently within the epithelial lining, but a few bodies were observed in the connective tissue walls. Histochemical reactions of hyaline bodies were similar to those of dental cuticles, but differed from keratin. Ultrastructurally, hyaline bodies were typed into two forms: lamellated and homogeneous. The lamellated bodies were composed of alternate electron-dense and electron-lucent layers. The homogeneous bodies were occasionally formed around granular material, mineralized masses and cholesterol clefts. Hyaline bodies adjoined epithelial cells via a basal lamina-like structure and half-desmosomes. Epithelial cells containing well-developed, rough surfaced, endoplasmic reticulum were seen adjacent to hyaline bodies. Ferritin-like granules were found in the cytoplasm of epithelial cells near hyaline bodies. By electron probe X-ray microanalysis, inorganic elements within the ferritin-like granules were the same in constitution as those in the outermost electron-dense layer of the lamellated bodies. By scanning electron microscopy, hyaline bodies displayed ellipsoidal and stick-like shapes. The present study suggested that hyaline bodies are particular products formed by odontogenic epithelium.