Ultrastructure of eosinophilic bodies in the degenerative surface epithelium of chronic hyperplastic oral lesions.

Eosinophilic bodies were located extracellularly in the dilated intercellular spaces of degenerative epithelial cells. They consisted of electron-dense amorphous material with many scattered mature fibrin fibers. Eosinophilic bodies were PAS positive, mucicarmine negative, alcian blue negative. A large number of lysosome-like bodies with homogeneous electron-dense content were present in the cytoplasm of the surrounding degenerative epithelial cells. The plasma membrane of these cells was intact and there was no outpouring of tonofilaments or keratohyaline granules into the intercellular spaces. With the results of the present study, it is suggested that eosinophilic bodies are probably an exudate of plasma fluid accumulated in the dilated intercellular spaces of superficial degenerative cells.