微小Ⅱc型早期胃癌の1例

A Case of Ⅱc Type Early Gastric Cancer (Minute Carcinoma)

　一般に1cm以下の早期胃癌の術前診断は，非常に難しい．X線診断に関してもしかりで，Ⅱcに関しては，潰瘍瘢痕を伴えば存在診断は比較的容易であるが，純粋のⅡcで，しかも微小になれば，これがX線写真にはっきり現われることは稀である．したがってそのX線症状を検討する機会も非常に少ない．

　本症例は，潰瘍瘢痕を含まず，ひろがり4×4mm，深達度mのⅡc型早期癌で，幸いX線検査で幽門前庭部にprofileniche，frontal nicheとしてはっきり現われ，術前診断は容易であった．これを機会に，本症例を使って微小Ⅱc型早期胃癌のX線症状の一面を検討してみた．

　A 53-year-old man visited our clinic with a chief complaint of pain in the epigastrium. X-ray examination of the stomach revealed on the lesser curvature of the antrum a niche, which in double contrast study was visualized as a tent-like projection outside the gastric contour. There was hardly any finding suggesting of malignancy, but poor distensibility of the wall on both the oral and distal sides of the tent-like niche we interpreted as owing to cancer infiltration, and partial gastrectomy was done. Macroscopically, the resected specimen showed a small ulceration in the antrum. Histologically it was tubular adenocarcinoma localized at the concaved spot (4 mm in the greatest diameter).

　X-ray signs worthy of mention in this minute carcinoma are as follows :

　1. The niche in profile was recognized as a small benign on without demonstrating any malignancy. In en face view it was of irregular shape, highly suggestive of malignancy.

　2. The area of decreased distensibility of the wall on both sides of the niche did not correspond in extent with that of cancer infiltration.

　3. Even in pictures where the niche was projected at some distance from the gastric contour, the outline was seen deformed.

　4. The roentgenogram of the resected specimen showed decreased distensibility in the area of cancer.