多彩な病像を呈した広汎なⅡb型早期胃癌の1例

A CASE OF EXTENSIVE Ⅱb TYPE GASTRIC CANCER WITH GROSS AND HISTOLOGICAL PATTERNS OF MARKED VARIETY

Ⅰ．はじめに

　早期胃癌への挑戦は胃集検とX線，内視鏡生検による精密検査により華々しい展開をみせ，その成果は本誌をはじめ単行本にも次々に発表され，基本型やその亜型はほぼ網羅された感がある．今日ではむしろ特殊型とか境界領域が問題とされ，その病像の多様性は尋常一様ではないように思われる．

　かかる早期胃癌に対する私ども外科医にとって術前，術中の癌の拡がりの診断は直接切除範囲決定に連なるが，（1）高木¹⁾も指摘するように，口側への癌の肉眼的拡がりと組織診の拡がりの不一致は残胃に癌細胞を残す可能性が少なくなく，一方（2）多発性早期胃癌の存在や，（3）Ⅱbの介入の問題が入ってくると，切除範囲決定の命題一っをとってみても，安易な術前診断は許されないであろう．

　他方，臨床病理学の立場からは，胃に潰瘍と癌が重なって見出された場合，そのいずれの病変が先行し，また両者の因果関係はどうあるかの問題は，潰瘍癌の発生や悪性サイクルの解明の形で繰返し論じられ興味ある点であるが，両者の関係は単純一様なものではないようである．

　私たちは多発性の潰瘍ないし潰瘍瘢痕の悪性化を疑い，厳重に経過を観察中の症例に，生検で悪性変化を見出し，術後切除胃の病理学的検索から潰瘍性病変とも関連した多彩な病像を示し，前に述べた術前診断の問題や病理学的解釈に示唆を与える広汎なⅡb型早期胃癌の1例を経験したので報告する．

　A 56-year-old man visited the authors' hospital because of a niche detected by a mass examination of the stomach. Two small ulcers surrounded by extensive atrophic mucosa were revealed by both x-ray and fibergastroscopic examinations on the anterior and posterior wall of the supraangular region. While under internal treatment, the patient was examined by biopsy as well, since the findings of two ulcerative lesions were such that malignancy could not be ruled out.

　The outcome was that mucocellular carcinoma was detected microscopically.

　The removed stomach showed very varied patterns. Tubular adenocarcinoma of low atypicality (Ⅱb) was found on the mucosa which was remarkably atrophied in a wide area around the gastric angle, followed by two ulcer lesions above-mentioned (Ⅲ). Added to this, besides a shallow depressed area (Ⅱc) surrounding the ulcer on the posterior wall, there were further found two localized, slightly elevated protrusions (Ⅱa) on the lesser curvature as well as an atypically swollen mucosal fold as of a worm (Ⅱa) in one of those converging rugae toward the ulcer scar on the anterior wall. On the mucosal surface of the resected stomach, these multicentric cancers veritably showed variegated patterns.

　Histological findings, no less diversified, further revealed that serial tubular adenocarcinoma was varied in its architecture. Because of the ulcer lesion on the anterior wall cellular atypia was more marked on that side, while on the posterior wall development of mucoid carcinoma was noticed. All these malignant changes developed only in the mucosal layer.

　This case offers some suggestive findings for elucidating variations of Ⅱb type carcinoma as well as the relationship between ulcer and early carcinoma.