Oligodendroglioma,oligo-astrocytomaの成長解析について—Ki−67 PAP染色

CELL KINETICS OF OLIGODENDROGLIOMA AND OLIGO-ASTROCYTOMA: Ki-67 PAP STUDY

　抄録　Oligodendroglia系腫瘍24例の増殖分画をcycling cellの核抗原と反応するKi−67モノクロナール抗体によるperoxidase anti-peroxidase （PAP）染色で明らかにした。平均陽性率は組織学的悪性度に相関しanaplastic mixed glioma （oligo-astrocytoma）（11.1％），　anaplastic oligodendroglioma （5.3％），isomorphic oligodendroglioma （2.8％），　mixed glioma （1.9％）の順であった。また血管の増生肥厚，構成細胞の多形性，および壊死巣の有無，二視野に占める陽性細胞の総数，核分裂率は陽性率と相関し，組織学的悪性度診断のcriteriaに成り得る。Ki−67 PAP染色による陽性率はoligodendroglia系腫瘍の組織学的悪性度診断の有用な補完情報である。

In order to determine the principal histologic features in distinguishing the "anaplastic" from the "well differentiated" oligodendroglioma and mixed glioma (oligo-astrocytoma), correlations between the growth fraction, and histologic grade and 6 histologic variables (vascular proliferation, cytologic pleomorphism, calcification, necrosis, cellularity, mitotic index) were studied in 24 patients.

The growth fraction was calculated as the per-centage of Ki-67-immunostained nuclei in frozen sections using Ki-67 monoclonal antibody. 6 his-tologic variables were checked with HE stain of paraffin-embedded tissue sections. The growth fraction was in general agreement with the histologic grade, in order of decreasing mean percentage, ranging from 11.1% (anaplastic mixed glioma) to 5.3% (anaplastic oligodendro-glioma), 2.8% (isomorphic oligo.) and 1.9% (mixed, grade II). There was a significant association between the growth fraction and 3 histologic variables (vascular proliferation, cytologic pleo-morphism, mitotic index) out of 6.

Thus, even though there exist some gaps be-tween these parameters in paraffin-embedded tis-sues and those in frozen sections, the percentage of Ki-67-immunostained nuclei is likely to be very valuable as a supplement information of histolo-gical grading and a prognostic indicator.