抄録
A 60-year-woman was admitted to our hospital complaining of the anastomotic reccurence tumor of rectum. She underwent sigmoidectomy for sigmoid colon cancer, extended left hemicolectomy for descending colon cancer and endoscopic-mucosal-resection for ascending colon cancer.
Endoscopic examination showed two lesions in the stomach, one was IIa in greater curvature of lower body and the other was depressed lesion in lesser curvature of antrum. The biopsy specimen of the former lesion was pathologically diagnosed as well～modalately differenciated adenocarcinoma.
Distalgastorectomy and super low anterior resection was performed. Three lesions were detected in the resected stomach. All three lesions pathologically showed carcinoma, IIa in the lower body showed tub1 (m) , IIc in the antrum showed papillary adenocarcinoma (m) , IIc in the prepyloric lesion showed tub1 (sm) .
Microsatellite instability (MSI) of all lesions and nomal mucosa of the stomach were positive. Rectal tumor was well differenciated adenocarcinoma and MSI of tumor and normal mucosa of the rectum was negative.
MSI of multiple cancer shows higher positive rate than that of single cancer. We think that MSI may be usefull for genetic diagnosis of gastric cancer as well as hereditary nonpolyposis colorectal cancer.
