色素内視鏡により発見されたⅡb型早期胃癌の1例

Superficial Flat Carcinoma, Ⅱb Type Detected by Using Dye Endoscopy, Report of a Case

はじめに

　胃診断学が確立すると共に，胃癌もできるだけ小さい状態で発見しようという試みが多くの人によりなされてきたが，内視鏡検査や生検がルーチン化してきた今日，決して至難のわざではなくなってきた．しかしⅡb型早期胃癌は肉眼形態的な変化に乏しく，通常の内視鏡検査のみではその把握は極めて困難である．そこで筆者らは色素法の併用，すなわちインジゴカルミン（IC）コントラスト法およびメチレンブルー（MB）染色法を同時併用することによりⅡb型早期胃癌を発見しえたので，その1例を報告する．

　Recently the diagnostic technic for gastric cancer seems to have made tremendous progress in the field of endoscopy. At the same, there has been a trend that our interests have been forcussed on the detection of Ⅱb type with little surface characteristics. In order to detect Ⅱb, we have routinely employed the dye endoscopy using both Indigocarmine (IC contrast method) and Methylene blue (MB staining method). In this paper a representative case of Ⅱb was reported.

　The patient was a 66 year-old male who had been treated as an out-patient for diabetes mellitus. Two month sprior to this admission he had workup of GI tract done because of abdominal discomfort off and on. Upper GI series disclosed slight irregularities along the lesser curvature of the mid-body of the stomach. Although an ordinary endoscopy showed no particular abnormalities, IC contrast picture showed an irregular and coarse granular mucosa with scattered redness. Such granular appearance inside the lesion was clearly dipicted as cancerous, and in fact, the biopsy showed signet-ring cell carcinoma. Grossly, however, the Ⅱb lesion could not be identified in partially resected specimen and the proximal boundary of cancer infiltration was not determined. Based upon the positive result for cancer cells microscopically at the frozen sectlon of proximal mucosa of surgical incision line, total gastrectomy was successfully carried out.

　The extent of cancer infiltration was confirmed by histologically investigating serial sections of resected stomach, i.e., 3.5×1.9cm in size. Therefore, it is no doubt that the dye endoscopy will contribute considerably to improving the diagnostic ability to detect superficial flat carcinoma (Ⅱb) by identifying these hitherto undetectable minute changes through the enhancement by IC and MB dyes of the topographic variations in the mucosa.