Electronmicroscopic observations were made on parietal cell of 39 cases of gastric diseases (gastric cancer 16, gastric ulcer 5, gastric and duodenal ulcer 3, duodenal ulcer 5, polyp 3, gastritis 3). The purpose of the present paper is to elucidate the cytopathological significance of lysosome like body, myelin figure, large vacuole and lipid droplet.
Relationship between parietal cell number, gastric acidity and these structures were also discussed. The results were as follows:
1) The ultrastructure of normal appearing parietal cell were similar as those observed by the most other investigators.
2) Nuclear deformity, mitochondrial deformity, lysosome like body (especially, secondary lysosome), myelin figure, large vacuole and lipid droplet were the changes or the structures rarely observed in normal appearing parietal cell.
3) Lysosome like bodies were identified ultrastructurally in 39 cases as lysosome, the most of which were the secondary lysosome. The parietal cell number was closely related to the presence of secondary lysosome.
4) Myelin figures were observed in parietal cells of 37 cases. In these cells, focal cytoplasmic degradation might be present.
5) The presence of large vacuole in 35 cases and the presence of lipid droplet in 28 cases were also thought to have some relationship with cell degradation.
6) Regarding to gastric acidity, decreased number of parietal cell was thought to be a more important factor than the presence of such an unusual structures as lysosome like body.