胃スキルスの臨床的ならびに病理組織学的考察

Clinical, Histopathological and Biochemical Studies on Scirrhus of the Stomach

　近年の胃X線および内視鏡診断学の進歩は目覚しく，X線的には二重造影法の開発・普及によって^1)～6)，また内視鏡的には内視鏡機器の改良^5)～11)あるいは生検や色素撒布法などの補助的診断法¹²⁾の導入によって，微小な早期胃癌の診断に代表される形態学的な胃診断学はほぼ完成の域に達したといっても過言ではない．しかし，粘膜面の凹凸性変化に乏しいⅡb型早期胃癌の診断^13)～19)や比較的短い期間に急激な進展を逐げたと思われるスキルスの早期診断^20)～27)にはいまだ問題が残されている．

　著者らはスキルスを胃壁内のびまん性の強度の線維化や癌浸潤のために胃壁が著しく肥厚・硬化し，胃内腔の狭窄を来す深部浸潤癌と解釈している²³⁾²⁵⁾．スキルスの大部分は癌の粘膜内進展範囲が広く原発部位の決定が難しい例が多いが，中村ら⁵²⁾は胃を胃体部・中間部・幽門前庭部の3部位に分けて，癌の粘膜進展部が主として占める部位別にlinitis plasticaを分類し，胃体部例が93例中55例ともっとも多く，幽門前庭例は1例もなかったという．著者らはスキルスを主として前庭部における胃壁の硬化を来し，幽門狭窄像を呈するlinitis plastica型と胃体部における胃壁内の強い間質反応のために著しい皺襞の肥厚を来すgiant folds型とに分類している．しかし，スキルスにおいては，胃壁全体の硬化が6カ月ないし1年と比較的短期間内に完了するものが多いため^20)～25)，スキルスのretrospective studyから胃体部の陥凹型早期胃癌の一部がその初期像と考えられてはいるが^20)28)～30)，その初期像を正確に把握することははなはだ難しい．

　Until present time, many clinical and fundamental studies on the definition, significance or development of scirrhus of the stomach have been presented.

　During the recent 4 years, 336 cases of depressed types of gastric cancer have been experienced in our clinic, including 65 cases of scirrhus of the stomach. First, in order to evaluate an early stage of this disease, retrospective studies were tried radiologically and endoscopically. After that, the histopathological study was not only tried, but the value of hydroxyproline was measured by Neuman ＆ Logan's method in gastric walls taken from the resected fresh specimens. The significance of the value of hydroxyproline in this disease is discussed, comparing with those in depressed type of early gastric cancer and control.

　The results are as follows:

　1) From the retrospective studies on 19 cases of scirrhus of the stomach, almost all cases showing “slight stiffness” of the gastric wall showed “leather bottle” appearance within 6～12 months in the barium-filled film.

　2) In an early stage of this disease in which stiffness of the gastric wall could not be recognized in the barium-filled film, an irregular shallow depressed lesion and/or stiffness or widening of mucosal folds were observed in double air contrast film taken by using a small amount of air. These findings were also seen in the corpus or angulus of the stomach.

　3) Histologically, 32 cases of scirrhus of the stomach resected consisted of 24 cases (75.0％) of undifferentiated carcinoma, 6 (18.7％) of poorly differentiated adenocarcinoma and 2 (6.3％) of well differentiated adenocarcinoma.

　4) In 24 cases (75.0％) fibrous proliferation was observed to be following the cancerous invasion in the submucosal layer, and in the remainder, fibrous proliferation and cancerous invasion occurred almost at the same time.

　5) Furthermore, edema preceding fibrosis in the submucosal layer was proved in 20 cases (62.5％).

　6) In 8 out of 62 cases of IIc or IIc＋III type of mucosal cancer of the stomach, edema preceding cancerous invasion or fibrous proliferation was observed in the submucosal layer.

　7) Either in scirrhus or in early cancer of the stomach, the value of hydroxyproline in edematous region was similar to that in fibrous one, and higher than that in control.

　8) From these results, it may be speculated that some cases of scirrhus of the stomach might have resulted from depressed type of early gastric cancer with diffuse edema in its submucosal layer of the corpus.