早期胃癌類似進行癌診断の指標と確かさ

The Index and Accuracy in the Diagnosis of Advanced Gastric Cancer Simulating Early Cancer

要旨　早期癌類似進行癌を独立した陥凹型進行癌とし，その肉眼型を決め診断の確かさを検討した．1978年から1989年までに経験した進行癌のうち5型は103病変（22.8％）で，そのうち，ひだ集中を伴いBorrmann型の周堤隆起を伴わない進行癌は82病変（79.6％）あり，これに同期間のひだ集中を伴う早期癌を加え，X線的に検討可能例（m：96病変，sm：91病変，進行癌：45病変）で検討した．周囲の隆起（++）をpm以下と診断すれば，早期癌の4.8％を進行癌と，進行癌の68.9％を早期癌と誤診する．ひだ集中（++）は潰瘍に伴うpm以下の組織学的変化を示すと考えられ，この指標では早期癌の29.9％を進行癌と，進行癌の35.6％を早期癌と誤診する．周囲の隆起（++）とひだ集中（++）を組み合わせると進行癌の73.3％が正診された．しかし，26.7％は早期癌としか診断できず，この内訳はpmに微小浸潤する5病変，pm以下にmassiveないし索状に浸潤した病変ではC領域の4病変，伸展が良好な2病変と小彎でひだ集中の軽度な2病変であった．早期癌類似進行癌の肉眼型は，ひだ集中を伴いBorrmann型の周堤の隆起を伴わない陥凹型癌のうち，著明なひだ集中を伴うか，あるいは陥凹周囲の隆起の明らかなものと定義され，著明なひだ集中を伴う例では胃壁の組織学的変化の深さが癌の深達度と判定されると考えられた．

　A macroscopical criteria of the so-called advanced gastric cancer simulating early cancer were tentatively established as an independent category of depressed type advanced cancer. One hundred and three lesions of type 5 advanced cancer accounted for 22.8% of the all advanced cancers experienced in the period of 1978-89. Forty-five lesions of advanced cancer which had converging folds but lacked Borrmann type mound-like elevation were compared with early cancers with converging folds. (These lesions were described radiologically as m 96, sm 91, and adv 45.)

　When surrounding elevation was the only index of diagnosis, misdiagnosis might have occurred in 4.8% of early cancers and 68.9% of advanced cancers. On the other hand, when converging fold was used as the only index, misdiagnosis might have occurred in 29.9% and 35.6%, respectively. When these two indices were used simultaneously, 73.3% of advanced cancers were diagnosed correctly. (Marked converging fold associated with ulcer is thought to indicate the presence of histological change in the proper muscle layer or below from it.) However, 26.7% (13 lesions) of advanced cancers were diagnosed as an early cancer even if both of these indices were used simultaneously. Such misdiagnosis occurred in the following cases; 5 cases with microscopic invasion into pm: 4 cases with massive invasion below pm in C area: 2 cases with easy expansion: 2 cases with the lesion on the lesser curvature and accompanying converging fold.

　Thus, macroscopic criteria of advanced cancer simulating early cancer should be the lesions of depressed type cancer accompanying marked converging fold or surrounding elevation. As a result, the depth of invasion in the gastric wall might be estimated based on the depth of histological change in the case with deep ulcer.