Immunohistochemical study of giant cell in glioblastoma.

The clinical and immunohistochemical features of supratentorial (5 patients) and cerebellar (1 patient) glioblastomas, in which giant cells were conspicuous were examined. Three of the patients died within 26 months after the first treatment, and the follow-up period is presently 1 year or less in the remaining patients. The giant cells either showed large and bizarre nuclei or were multinucleated. Both giant and smaller cells excluding neuronal, endothelial and infiltrative cells were positive for GFAP, vimentin, and alpha-1 anti-chymotrypsin. The strong positivity for PCNA staining indicated that the capacity of the giant cells to synthesis DNA was preserved. DNA fragmentation, measured by the terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine-5'-triphosphate (dUTP)-biotin nick end labeling method, was observed in only 1 patient, who had received radiotherapy just before biopsy, and none of the patients showed bcl-2 positivity. Mutant type of p53 tumor suppressor gene was observed in the giant cells of 3 patients. Giant cell in glioblastoma is of glial origin, synthesizes DNA, and its progression may be related to tumor suppressor gene.