Anaplastic astrocytoma of the adult cerebrum. Prognostic value of histologic features.

Initial biopsy and resection specimens from 78 cerebral astrocytomas with anaplastic foci occurring in adults were examined for the presence of five specific histologic features traditionally considered indicative of anaplasia. Anaplastic astrocytomas with foci of tumor necrosis had been classified as glioblastoma multiforme and excluded from this analysis. Median actuarial survival was shorter for patients whose tumors contained vascular endothelial proliferation (3.5 years versus 5.5 years) or greater than 1 mitosis per 10 high power microscopic fields (1 year versus 5.5 years). No correlation with survival was found for estimation of nuclear pleomorphism and cell density or the presence of secondary structures. Vascular endothelial proliferation and increased mitotic activity may serve as prognostically significant histologic markers in cerebral astrocytomas of intermediate malignancy.