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The role of the biopsy in diagnosis of early gastric cancer.

In order to determine the reliability of endoscopic biopsy in diagnosis of early gastric cancer, and to clarify the problems with biopsies, preoperative endoscopic biopsies from 771 early gastric cancer cases were reviewed and analyzed clinicopathologically in comparison with surgically resected specimens. The 771 cancers were surgically resected at the National Cancer Center Hospital during the period from 1972 to 1982. Definite histological diagnosis was obtained in 87.4% of the carcinomas at the initial biopsies. Repeated biopsy raised the percentage of correct definite diagnoses to 96.1%. False-negative (including suspicion of cancer) diagnosis was most frequent in the case of depressed lesions (50 lesions). Half of the false negatives were found to be due to sampling errors by the endoscopists. The other half of these 50 lesions were diagnosed as "suspicious of malignancy" because of the histological difficulty in differentiating early gastric cancer from regenerative atypia with intestinal metaplasia, or because there was not enough information, or for the other reasons. Most of the 31 false-negative diagnoses at the initial biopsy from elevated lesions were reported as adenoma (group III) or suspicious of carcinoma (group IV), indicating that differential diagnosis between well-differentiated adenocarcinoma and adenoma is very difficult. The result of the present study suggests that repeated biopsy from correct sites and discussion of the lesions between clinicians and pathologists are very important.