Ⅱb型早期胃癌の1例

A IIb Subtype Early Cancer of the Stomach, a Case Report

　X線，内視鏡検査，生検などの診断技術の進歩に伴い，微小胃癌も比較的容易に診断できるようになった．しかし，Ⅱb型早期胃癌については術前に診断できた症例はいまだに少ない．われわれは，内視鏡検査および生検により術前にⅡb型早期胃癌と診断しえた1症例を経験したので報告する．

　A 42-year-old man, who had no subjective symptoms, visited our department because rigidity of the lesser curvature of the mid-corpus had been pointed out at a gastric mass survey in Oct. 1974. As the initial endoscopy revealed a discolored area adjacent to the pyloric ring on the posterior wall near the lesser curvature, we performed biopsy, which was positive for cancer. The diagnosis was IIb subtype early gastric cancer. Roentgenographic examination did not reveal any definite changes. To ascertain the accurate area of cancer, we tried endoscopic dye scattering method, but we were unable to find any difference in coloration between the areas of cancer and non-cancer because cancer foci were covered by the surface mucosa the same as the surrounding mucosa. Re-biopsy was done in the areas adjacent to the site of initial biopsy which was positive for cancer. Only in the specimens taken form the discolored area were we able to confirm cancer, so that we concluded that the extent of cancer was limited to the small area of discoloration. Even in the resected specimen after subtotal gastrectomy was there any difference in niveau and coloration between the area of cancer and the neighboring mucosa. Macroscopically, we could not accurately identify the area of cancer. The lesion measured 13 mm by 12 mm. Cancer was localized in the middle layer of the mucosa. There was no erosive changes, and the lesion was covered by the mucosa showing intestinal metaplasia quite similar to the surrounding mucosa. Histologically it was signet ring cell carcinoma.