PROLIFERATION OF GEMISTOCYTIC CELLS AND GLIAL FIBRILLARY ACIDIC PROTEIN (GFAP)-POSITIVE OLIGODENDROGLIAL CELLS IN GLIOMAS - A MIB-1 GFAP DOUBLE-LABELING STUDY/

Large gemistocytic cells are well-known elements of glial tumors. Rece ntly, miniature gemistocytic cells and neoplastic glial fibrillary aci dic protein (GFAP)positive oligodendroglial cells, which are regularly seen in oligodendrogliomas, have been termed ''transitional cells''. The proliferative activity of the gemistocytic cell types and the GFAP -positive (gliofibrillary) oligodendrocytes was determined in eight as trocytomas, seven gemistocytic astrocytomas, eight glioblastomas, two monstrocellular glioblastomas, seven oligodendrogliomas and three mixe d oligo-astrocytomas by immunohistochemical staining of the proliferat ion marker MIB-1 in combination with immunostaining for GFAP. Both lar ge gemistocytic cells and the transitional cells showed cytoplasmic GF AP-positive staining. Neither in the classic gemistocytes nor in the m inigemistocytes nuclear immunostaining for the MIB-1 antibody was obse rved. In contrast, MIB-1 staining was seen in the gliofibrillary oligo dendrocytes. It is concluded that both large and miniature gemistocyti c cell types contrast with gliofibrillary oligodendrocytes by their in ability to proliferate.