Use of nucleolar organizer regions in the histopathological diagnosis of colorectal epithelial neoplasia.

The AgNOR technique, specific staining for nucleolar organizer regions, was applied to twenty-seven lesions (sixteen tubular adenomas with low grade atypia and eleven well-differentiated adenocarcinomas invading the submucosa) of colorectal epithelial neoplasia, to examine the possibility of its application to histopathological diagnosis. The mean AgNOR number per adenoma nucleus (2.62 +/- 0.16) was significantly higher (P less than 0.01) than that per carcinoma nucleus (2.28 +/- 0.25). The mean cross-sectional area and the maximum diameter of carcinoma AgNORs (1.91 +/- 0.20 micron2 and 1.89 +/- 0.09 micron, respectively) were significantly larger than those of adenoma (1.15 +/- 0.17 and 1.45 +/- 0.11, respectively). The result of the discriminant analysis using these two variants corresponded to the pathological diagnosis with an accuracy of 96.3% (26/27). We thus concluded the AgNOR technique to be one of use in the histopathological diagnosis of colorectal epithelial neoplasia.