胃粘膜下腫瘍の2例

TWO CASES OF SUBMUCOSAL TUMORS OF THE STOMACH

Ⅰ．はじめに

　最近わが国において，胃疾患診断の水準は胃カメラの発明，胃X線，細胞診の開発，さらには胃生検の導入により飛躍的発展をとげた．その結果癌が早期の段階で容易に発見されるようになってきた．

　一方胃癌との鑑別を要するもののひとつとして粘膜下腫瘍が注目されるようになり，その報告例も増加しつつある．胃粘膜下腫瘍はX線的には存在診断は比較的容易であるが，質的診断は難かしく，胃細胞診，生検も無力に等しく，内視鏡診断が最も重要である．

　われわれは胃粘膜下腫瘍の2例を経験したので症例を呈示するとともに，その内視鏡診断につき文献的考察を加えたので報告する．

　Case 1: a 47-year-old male. Though he had no subjective complaint, there was found by periodic x-ray examination of the stomach a shadow defect in the greater curvature side of the pyloric antrum. By endoscopy it was visualized in the same site as a protrusion suggesting of a submucosal tumor. At operation a neoplasm, measuring 3.0×2.5 cm, was observed in the greater curvature side of the antrum. Histologically this was confirmed as a leiomyoma.

　Case 2: a man 69 years of age. While he was treated in the outpatients' clinic on account of essential hypertension, he noticed loss of weight. X-ray examination of his stomach, done by way of precaution, revealed a protruded lesion at the gastric angle near the posterior wall. This lesion, endoscopically confirmed as a submucosal tumor in the same site as of the x-ray picture, later proved to be aberrant pancreas in the course of the operation.

　Two cases here described as well 22 cases of submucosal tumors of the stomach reported hitherto in the literature have been investigated with respect to their endoscopic diagnosis, especially their discrimination from one another. As for their incidence, leiomyoma comes first, (42 per cent) followed by eosinophilic granuloma (17 per cent), aberrant pancreas (14 per cent) and neurinoma (11 per cent). Predilection sites of leiomyoma and neurinoma are in the upper segment of the stomach and the latter is most often found in its lesser curvature side. The size of these tumors very much varies and that of the aberrant pancreas and eosinophilic granuloma is mostly less than 2 or 3cm in diameter.

　Endoscopically the ratio of the breadth of the tumor as against its height is in leiomyoma 2.2, 2.5 in neurinoma, 2.8 in aberrant pancreas and 3.5 in eosinophilic granuloma. The angle which the tumor forms with the plane of the surrounding mucosa is in leiomyoma 119°, being nearest to the right angle; the rest are more gently sloping: in neurinoma it is 130°, in aberrant pancreas 142° and in eosinophilic granuloma 144°. The surface of the aberrant pancreas and angioma is rather irregular, while in eosinophile granuloma it is uneven. Lipoma is characterized by its yellowish hue and lobulation.