三重複早期胃癌の1例

Triple Lesions of an Early Gastric Cancer, Report of a Case

　われわれは幽門前庭部後壁のⅡa＋Ⅱc型早期癌，幽門前庭部前壁のⅡa＋Ⅱc，胃角部前壁のⅡc型早期癌の三重早期癌の1例を経験したので報告する．

　なお，これらの病変のうち幽門前庭部後壁のⅡa＋Ⅱc型早期癌はその一部が十二指腸球部に脱出し，形の診断を難しくした．また，この病変は胃生検でGroup Ⅲと診断された標本もあり，9カ月前の内視鏡フィルムでは病変は小さく，表面も平滑で癌と考えにくい点もあったのでこの病変の診断過程についても述べる．

　A 68-year-old woman, who had been followed up for the polypoid lesion in the antrum for nine months, was referred to our hospital for further examination of the lesion. She had no subjective symptoms, and no abnormal physical signs were demonstrated. X-ray and endoscopic examination revealed the polypoid lesion around the depressed area on the posterior wall of the antrum, a part of which prolapsed into the duodenal cap. The lesion was composed of granular mucosal changes uneven in size and shape. Judging from its size, measuring over 2 cm in diameter, malignancy was highly suspected. A polypoid cancer as a whole could not be considered, however, because of its distensibility, ill-defined proximal border, and the histological diagnosis of Group Ⅲ and Ⅳ in biopsy specimens. In addition, endoscopic photographs taken nine months before the operation failed to reveal any malignant findings. Namely, the lesion was small with flat surface. A part of biopsy specimens showed atypical tubular structures of Group Ⅲ. Apart from this lesion, type Ⅱa+Ⅱc early cancer on the anterior wall of the antrum and type Ⅱc early cancer on the anterior wall of the angulus were detected.

　Gross specimen of the resected stomach showed type Ⅱa+Ⅱc early cancer, measuring 3.5×3.0 cm, on the posterior wall of the antrum, type Ⅱa+Ⅱc early cancer, measuring 1.5×1.0 cm, and type Ⅱc early cancer, measuring 1.5×1.0 cm, on the anterior wall of the angulus. Three lesions were independent. Two ulcer scars were also seen on the body.

　Microscopically all three cancers had identical structures of well differentiated adenocarcinoma. In the section of the elevated lesion on the posterior wall of the antrum, papillary proliferation was also demonstrated, and the cancerous structures were limited mostly to the mucosa, slightly invading the submucosal layer. Atypical tubular structures not graded as cancer coexisted in a part of the lesion and atypical epithelium with some suspicion of well-differentiated adenocarcinoma.

　This is a rare case of triple lesions of early gastric cancer. A special attention was paid to the cancer on the posterior wall of the antrum. In such a polypoid lesion, we emphasize the importance of revealing fine property of the surface by x-ray and endoscopic examination with biopsy. In addition, the size of the lesion should be considered in diagnostic process.