早期胃癌の直下に囊胞を有した1例

A CASE OF SUBMUCOSAL CYST DIRECTLY BENEATH AN EARLY CANCER

はじめに

　近年，胃X線，内視鏡，生検，細胞診などの各種検査法の普及発達にともない，早期胃癌および粘膜下腫瘍その他各種疾患の診断が急速に進歩した．胃囊胞は胃良性疾患のうちでもまれな疾患とされ，文献的報告も散見するにすぎないが，筆者らはⅡc型早期胃癌の直下に囊胞を有した1例を経験したので報告する．

　In accordance with recent developement of examination methods in diseases of the stomach, there have been rapid progress in their diagnosis, as exemplified in the case here described which was that of an early gastric cancer of Ⅱc type with a cyst directly beneath it.

　The patient is a 62 year-old man. There is nothing noteworthy both in his familial and past histories. He came to the authors' hospital as he was advised to undergo a thorough check-up after he had been examined in a gastric mass survey in November 1968. Roentgenologically from the middle part of the corpus way to the incisura there was found a shallow depression stretching over the anterior and posterior walls with the lesser curvature as its center, together with abrupt cessation, thinning and worm-eaten state of the mucosal folds converging toward the lesion. It was diagnosed as Ⅱc type early gastric cancer. In the meantime, a smooth, broad-based protrusion was endoscopically observed within Ⅱc depression. This was diagnosed as a submucosal cyst directly beneath it. Biopsy under direct view disclosed carcinoma simplex mucocellulare. Operation was accordingly performed under the preoperative diagnosis of Ⅱc type early gastric cancer with a submucosal cyst directly beneath it.

　Gross finding of the resected stomach confirmed the preoperative diagnosis. Histologically the lesion was carcinoma simplex mucocellulare, extending widely within the mucosal layer with no vertical infiltration from the submucosal layer downward. In the submucosa there were cysts of various sizes, some solitary and some grouped together. This case was diagnosed simply as early gastric cancer, but on reflexion it seems that the existence of a depression too much absorbed the examiner's attention to fully notice a very low, broad-based tumor in a part of the depression, so that delineation and interpretation of the submucosal cyst was unsatisfactory. As it is apt to be overlooked also by endoscopy, scrupulous care must be paid in the observation of a gastric lesion. The cyst in this case, according to Palmer's classification, is akin to “endogenous cyst”, a rarely encountered tumor. There is no histological finding to corroborate any relation between the cyst and cancer.