胃底腺領域の早期癌の診断

Detection of Early Cancers Located in the Fundic Gland Region of the Stomach

要旨　胃底腺粘膜から発生した早期癌52例66病変の特徴とそのX線，内視鏡診断について検討した．性別では女性47例（90％），男性5例（10％）で女性に多かった．年齢的には40～59歳に多くLP型癌の性，年齢別頻度に類似性がみられた．肉眼分類ではIIc：29病変，Ul（＋）またはUl-s（＋）のIIc：31病変，IIb：6病変で全例未分化型癌であった．Ulの有無と深達度をみるとUl（－）ではm癌が多く，Ul（＋）ではsm癌が多い傾向がみられた．大きさと深達度をみると2cm以下の病変でもsm癌が41病変中15病変，37％あり，比較的小さな時期にsmへと浸潤する傾向がみられた．大きさとUlの有無をみると2cm以下で41病変中17病変，41％にUlがみられ，小さな病変でもUlを形成しやすい傾向がみられた．LP型癌の早期の段階がsm癌で粘膜面よりsm以下での浸潤範囲の広範なもの，あるいは潰瘍を伴わないsm癌がその可能性があるものと考えるが経験された症例では非常に少ない．ルーチンX線検査で単発例では前壁，後壁とも25％の見逃しがみられ，後壁でも見逃されやすく，ひだ集中の有無と見逃しとには関係が少なかった．胃底腺領域内の早期癌の多発例は21％と頻度が高く，診断上注意する必要がある．胃底腺領域内の早期癌のX線像の特徴は浅い不整形の陥凹であり，内視鏡像の特徴は褪色である．

　Sixty-six lesions (52 cases) of early cancer which arose in the fundic gland region were analyzed regarding histopathological, endoscopical, and radiological characteristics. Fifty-five lesions were clinically detected, with remaining 11 lesions histopathologically.

　Patient population was comprised of 47 females (90%) and 5 males (10%), with the peak prevalence between the ages of 40 and 59, similar to linitis plastica type cancer.

　Gross classification included 29 type-Ⅱc lesions accompanying no ulceration, 31 type-Ⅱc accompanying ulceration (both active and scarring), and 6 type-Ⅱb. All 66 were poorly differentiated cancers.

　As to the relationship between the presence of ulceration and the depth of cancer invasion, mucosal cancers were more frequently found in the cases without ulceration. In contrast, submucosal cancers were more frequently found in the cases ulceration.

　As to the relationship between the size and the depth of cancer invasion, 37% of the lesions smaller than 2 cm in diameter were submucosal cancers (15/41), implying the cancerous invasion to the submucosal layer at earlier stages.

　As to the relationship between the size and presence of ulceration, 41% of the lesions smaller than 2cm in diameter were accompanied by ulceration (17/41), indicative of probable ulcer formation when small.

　Twenty-five percent of the lesions (single) located on the anterior wall were not correctly diagnosed. The same was true for the lesions on the posterior wall. Even the lesions on the posterior wall were overlooked not infrequently.

　There was no definite relationship between the presence of ulceration and eluded cases.

　Twenty-one percent of early cancer cases located in the fundic gland region had multiple cancers. This fact should be of clinical importance.

　The characteristics of those cancers were irregularlyshaped depression radiologically and discoloration endoscopically.

　Linitis plastica type submucosal cancer is generally considered relatively early cancer in which the extend of cancer spread in the submucosal layer is far greater than that in the mucosal layer.

　On the other hand, submucosal cancer accompanied by “no ulceration” is closely associated with the cancerous growth of linitis plastica type or regarded as the precursor of linitis plastica cancer.

　However, such submucosal cancer cases were rarely encoutered in our case series.

　In the light of the status quo of diagnostic obility of early cancers located in the fundic gland region, not a few problems still remain unresolved.