An immunohistological method for estimating cell growth fractions in rapid histopathological diagnosis during surgery.

In the past, it has been impossible to carry out immunohistological staining as part of a rapid histopathological diagnosis during surgery because the available methods were too time-consuming. The present report introduces a rapid indirect immunoperoxidase method that requires only 10-12 min. Thus, the immunological characterization of tumour cells may now be applied as an additional parameter for histopathological diagnosis during surgery. In this first attempt, the monoclonal antibody Ki-67, which reacts with a human nuclear antigen present in proliferating cells and absent in quiescent cells, was applied with a new immunostaining method and the results were compared with those obtained by the more time-consuming routine immunohistological method. There was no significant difference between the percentages of Ki-67-positive cells determined with the two methods in normal or neoplastic human tissues. Since knowledge of the growth rate of a malignant tumour may be of prognostic and/or therapeutic value in individual cases, it might be useful to routinely apply this new approach for histopathological diagnosis during surgery.