[A clinicopathological study of 3 dimensional structure in adenoma of large intestine]

The 3 dimensional reconstruction electrocomputor was used to study the distribution of atypia epithelia in 50 cases of large intestinal adenoma which were taken by fibercoloscopic resection. The 0.2 mm interval serial sections were stained with HE. Carcinomatous changes in adenomas were found in 17 cases, the rate being 34%. The average size of intraadenoma carcinoma being 3.4 times that of adenoma. The larger the adenoma, the higher the cancer rate. But the adenoma to cancer rate is high (25%) in Ips type adenoma of small size with pedicle. The size of adenoma is not associated with allotype incidence. 14 of the 17 cases were detected by study of conventional paraffin block slides, missed diagnosis rate being 18%. The serial sections must be made with intervals less than 0.6 mm in order to prevent missed diagnosis. This method is also of significance to determine if the excision site is cancer free.