大彎側の病変―レントゲンの立場から

X-RAY DIAGNOSIS OF THE LESION IN THE GREATER CURVATURE OF THE STOMACH

Ⅰ．はじめに

　現在，胃体部大彎側の陥凹性病変をまともに取り上げることは極めて因難である．それというのも，第1に，陥凹性病変というと，わが国では，まず早期胃癌Ⅱcを考えるであろうが，胃体部大彎側のⅡcはまだごく少数しか発見されていないからである．それかといって，他の部位のⅡcや胃体部大彎側の進行癌や潰瘍で代理できるものでもない．第2に，大彎側の良性潰瘍の頻度がごく少ないからである．文献を調べてみても，大彎側の良性潰瘍のX線診断について，かなり多くの報告はあるが，ほとんどが症例報告の形をとっており，そして，ついでに良性・悪性の鑑別診断にふれるといった程度のものばかりである．このさいの大彎側潰瘍は，あくまで胃全体の大彎側潰瘍であって，胃角部や幽門部のものも含まれている．胃体部大彎側と限定した文献は見当らない，なお，大彎側の潰瘍性病変についての文献は，その大部分が英語または仏語であるのも1つの特徴といえよう．

　私どもの最近の症例を集めてみても，胃体部大彎側と限定すると，潰瘍にしても，陥凹性の早期癌（ⅡcやⅡc＋Ⅲなど）にしても，症例が少なすぎて，とても総括的な議論はできそうにない．このようなことを前提にして，できるだけ多くの文献を調べ，また，私どもの経験例にもとづき，胃体部大彎側の陥凹性病変のX線診断について検討することにする．

　Of the depressed lesions originating in the greater curvature of the gastric body, the detected number of benign ulcer and early carcinoma is so small that over-all estimation of them may not be possible.

　The deductive conclusion are mostly based on the cases we have encountered, ranging over the literature being an aid of the study.

　(1) It is not infrequent that benign ulcer of the greater curvature may be erroneously diaggnosed as malignant one, because it often shows “niche encastrée” in roentgen sign. The roentgen criteria differentiating between benign and malignant nature may depend upon whether a niche and its surrounding area are smooth or irregular.

　Both double contrast radiograph and compression picture are in this respect very important for further discrimination; these two methods should be fully emplayed to establish the nature of any lesion found in the greater curvature side of the gastric corpus.

　(2) In the greater curvature side, even a minute lesion such as ulcer scar or early carcinoma (Type Ⅱc) may show depressed appearance of the margin, “aspect encastree”, and this finding may depend on a certain change of a patient's position and degree of the barium-filled stomach, because the roentgen site of the greater curvature may not always correspond with its anatomical site.

　In general, barium-filled film and double contrast radiograph can demonstrate this kind of abnormality more effectively than mucosal study.

　(3) Mucosal folds are formed more markedly in the greater curvature side in other parts of the stomach. Consequently, the gross finding or abnormality may be better demonstrated, when examination by the prone and supine double contrast method or compression study is performed in an over-distended state of the stomach with contrast media and air.