[Immunohistochemical study of proliferative cells in colorectal adenoma and carcinoma]

The distribution of proliferating cells was studied in colorectal carcinoma by immunohistochemistry using monoclonal antibody-DNA polymerase alpha and Ki-67. Colorectal carcinoma was classified into two types by growth mode: (1) intramucosal polypoid growth carcinoma and (2) non-polypoid growth carcinoma. The labeling index of anti-DNA polymerase alpha and Ki-67 in non-polypoid growth carcinoma was significantly higher than in polypoid growth carcinoma. The labeling index of polypoid growth carcinoma was significantly higher than adenoma. The proliferating cells in polypoid growth carcinoma and adenoma were mainly distributed in the upper third of intramucosal neoplastic gland. However, in non-polypoid growth carcinoma, the proliferating cells of intramucosal lesion were scattered mainly in the lower third along the neoplastic gland. The distribution pattern of proliferating cells in early carcinoma with non-polypoid growth were similar to those of non-polypoid growth advanced carcinoma. These results suggested that submucosal invasion occurred more rapidly in intramucosal non-polypoid growth carcinoma.