急性胃病変と慢性胃潰瘍の病理

Pathological Aspect of Acute Gastric Lesion and Chronic Gastric Ulcer

　急性胃病変は，ストレスによるもの，各種薬剤によるもの，胃の血管性変化に基づくものの3つに分類されている¹⁾．ストレスによるものとしては，熱傷によるCurling ulcer，頭部外傷や脳手術後にみられるCushing ulcer，骨折や外科手術後にみられる急性潰瘍などである．薬剤によるものとしては，解熱，鎮痛消炎剤や化学療法剤，経口糖尿病治療剤，副腎皮質ホルモン，抗癌剤などであるが，このほかにもアルコール摂取，腐蝕剤の嚥下によっても起こる．胃の血管性変化に基づくものとしては，老人などの動脈硬化性変化の強いものに胃の微小循環に悪影響を及ぼすニコチンなどの作用が加わると，急性潰瘍が容易に発生するというものである．

　しかし，その用語については，急性胃病変のほかに，急性出血性胃炎，ストレス潰瘍，急性潰瘍などがあり²⁾，はっきりした形態学的な裏づけによるものではなく，あくまでも臨床的な総称と考えられている．少なくとも，先に述べた誘因がはっきりしていることや，病変が多発性，不整形をとり，比較的浅く，出血を伴いやすく，胃のどの部分にも発生することなどが共通している．

　A distinctive feature of acute gastric lesion or acute gastric ulcer remains obscure, and their clinical and morphologic characteristics remain to be defined.

　For over the last two years, we have studied characteristic features of acute gastric ulcer by investigating six cases of histologically proven acute gastric ulcer and comparing their histological findings to chronic gastric ulcer.

　The all six cases had severe hematoemesis and melena which couldn’t be controlled by convensional management. Therefore, all of them underwent gastrectomy and the resected specimens were used for investigation.

　Analysing these cases, we found that all acute gastric ulcers, in contrast to chronic ones, were shallow enough to be classified as and exposed vessels were always noted in their ulcer bases.

　On the other hand, their ulcer size depended on their location, namely ulcers in the body of the stomach were small and ulcers adjacent to acid secreting mucosa were large. It was also found that occurrence of ulcer was more predominant in the area of fundic glands.

　In acute gastric ulcer, mucosal atrophy was frequently recognized in the area of fundic glands where erosion was often noted.

　On the other hand erosions tend to develop at the body of the stomach in acute gastric ulcer and their histological evaluation disclosed hemorrhagic necrosis.

　However, erosions associated with chronic gastric ulcer were histolytic type necrosis and much less in quantity.

　We feel that the possible mechanism of development of acute gastric ulcer could be due to marked mucosal circulatory disturbance by unknown causes, then it produces erosion and peptic ulcer in the atrophic mucosa. Finally, conjested submucosal vessels protrude into their bases and produce massive bleeding.