Abstract
Since the protruding type of gastric atypical epi-therium (ATP) had been well known to he a quite resemble to early gastric cancer type Ha in the clinical macroscopical features, in the present study, the ATP was further studied to know its nature as to whether this type of ATP might have a possibility to be becoming in showing malignant signs in future or not by the observations of its clinical features upto 5 years and also using autoradiography with 3H-thymidine, which indicated mainly cell mitosis in it. Most of ATP located in areas of gastric antrum and angle were under 2 cm diameters and found in 60 years old human been, while the early gastric cancer type ha in the same areas was found mainly in 50 years ones. Another difference was found in their sizes. The early gastric cancer type IIa was much larger than that of ATP. In order to know the possibility that the ATP might show gradual change in malignancy in long periods of time, 1.4 out of 70 patients were followed up by performing a couple time of endoscopic biopsy a year upto 5 years, average 2 years, and it was found that there was no sign of malignancy in all courses of the study. Although a number of cells labelled with 3H-thymidine had heed known to be increased in all of gastric cancers, there was no increase of labelled cells in ATP as well as that found in patients with gastritis and in normal gastric mucosa. It was also noted mat the labelled cells were located only in the surface of the lesions in ATP while they were uniformly located within all parts of cancer. The facts suggested strongly that the ATP itself had a quite clear nature which was difference from the cancer. Because some investigators suggested that the intes-tinal metaplasia, which was not a cancer, was a similar in its nature to the ATP, the comparison in each was made by the labelling technique with 3H-thymidine. In the intestinal metaplasia, labelled cells located in the areas of 450-600μ from surface while they were located at the areas of 50-200μ from the surface in the ATP, indicating that the ATP was not a similarr to an intestinal metaplasia.
