早期胃癌類似進行癌の病理組織学的検討

Histopathological Study on Early-like Advanced Gastric Carcinoma

要旨　早期胃癌類似進行癌の大部分は陥凹型で，癌の深部浸潤の拡がりが粘膜内癌のそれよりも狭いものが多い．また癌の深部浸潤形式は微小浸潤，あるいは散在性浸潤で，癌細胞量は少ないものが多かった．このような浸潤形式を示す要因として癌巣内での繰り返した潰瘍の存在と，それによる持続した胃壁内の高度な線維症が最も大きく，それと相まって肉眼での深達度診断を困難にしていると考えられた．これに対して陥凹型早期胃癌の形態を保持しているが，肉眼的には進行癌とされるBorrmann型との中間型は消化性潰瘍の併存頻度が低かった．また肉眼的には粘膜ひだの集中を伴い消化性潰瘍の存在が疑われる症例でも，胃壁内の線維症は軽度，かつ癌細胞はびまん性浸潤を示していた．これらのことより陥凹型胃癌の肉眼形態に与える影響は癌の深部浸潤形式と同時に，消化性潰瘍の線維症が最も大きい．

　Most of early-like advanced gastric carcinomas macroscopically exhibit depression with peptic ulcer and scar. The mode of invasion of tumor cells were classified into three types. The first type is microinvasion of tumor cells, the second scattered invasion, and the third massive invasion. In those types of tumor cell invasion beyond the submucosal layer, micro- and scattered invasions were most frequently seen. There were small areas of tumor cell proliferation. Furthermore, these early-like advanced gastric carcinomas with micro- or scattered invasion of tumor cells beyond the submucosal layer are accompanied by peptic ulcer or ulcer scar and marked fibrosis of the gastric wall. The fibrosis is the result of repeated ulceration, serving as an inhibiting factor of tumor cell invasion or proliferation in the gastric wall.

　On the other hand, in the cases with massive invasion or proliferation of tumor cells in the gastric wall, there are few or no fibrosis with or without peptic ulcer. These cases were similar to Borrmann type advanced gastric carcinoma. Early-like advanced gastric carcinoma with repeated peptic ulcer is that of slow growing nature. It is impossible to make a diagnosis of advanced carcinoma solely based on macroscopical findings.