PROLIFERATIVE ACTIVITY OF ACOUSTIC NEURILEMOMAS WITHOUT NEUROFIBROMATOSIS DETERMINED BY MONOCLONAL-ANTIBODY MIB-1

Microscopic sections obtained from paraffin blocks of 30 consecutive n eurilemomas stored in 1989 were investigated immunohistochemically wit h the new monoclonal antibody MIB 1 directed against recombinant parts of Ki-67 antigen. The immunohistochemical staining was carried out on dewaxed microwave-oven-processed paraffin sections of formalin-fixed tumour tissues. The labelling index (LI) obtained was below 1% in 21 c ases, 1-3% in 7 cases and more than 3% in 2 cases. There was no correl ation between the LI and the age of the patients or the tumour size. T he major advantage of MIB 1 over previous immunohistochemical methods is its usefullness in long preserved sections which are ideal for retr ospective studies.