Ⅲ型早期胃癌の1例

Type Ⅲ Early Gastric Cancer, Report of a Case

要旨　患者は，61歳男性．胃角上小彎に開放性潰瘍病変を認め，X線的にも内視鏡的にも悪性の診断は困難であったが，生検で癌が証明されたため，外科的切除が施行された．術後の病理組織学的検索の結果，Ul-Ⅳの開放性潰瘍の肛側に2×1mm大の中分化型腺癌が認められ，深達度mのⅢ型早期胃癌と診断された．極めて微小な癌巣を有した本症例は，いかなる潰瘍病変に対しても，厳重かつ的確な生検の重要性を示唆した．

　A 61-year-old man who had been diagnosed as having gastric ulcer at another hospital visited our hospital for further examination. The roentgenographic and endoscopic examinations detected two ulcerative lesions with converging folds; one was located on the lesser curvature of the upper part of the gastric body and the other was on the lesser curvature of the gastric angle. Our clinical diagnosis for both two lesions were benign ulcers. However, histological examination of the biopsy specimen taken from the anal margin of the latter ulcerative lesion revealed cancer. Histological examination of the subtotally resected stomach revealed moderately differentiated adenocarcinoma in the latter lesion and cancer localized within mucosa. The cancerous area was very tiny, measuring about 0.2×0.1 cm in size, and localized only at the margin of the ulcer. Macroscopic type was diagnosed as type Ⅲ. Only 13 cases out of 2,120 of early gastric cancers in our hospital during the period from 1962 to 1989 were classified as type Ⅲ. Therefore, the incidence of type Ⅲ cancer is considered to be very low (0.6%). Although the malignant endoscopic findings can be retrospectively pointed out almost in half of these cases, no case could be diagnosed as type Ⅲ. The accurate differential diagnosis between type Ⅲ cancer and benign ulcer by endoscopic examination is considered to be very difficult. Even though endoscopic findings of an ulcerative lesion are suggestive of benign nature, endoscopists should not deny existence of cancer in the lesion. Gastric ulcerative lesions should be followed up closely with endoscopic and histological examination as far as possible.