The recognition of the anaplastic variant of oligodendroglioma is difficult
, since it is not easy to identify histological prognostic factors. Among t
he latter, vascular productive changes have been inconsistently put in rela
tion with survival. In 95 cases of operated oligodendrogliomas, endothelial
cell hyperplasia, microvascular proliferations and capillary density were
studied by histological and immunohistochemical methods. Capillary density
was evaluated on CD31-stained sections by a grid of 100 squares placed in t
he ocular of the microscope. Statistical analysis was performed in order to
compare these parameters with survival. A nodular growth pattern was obser
ved more frequently among tumor grades 3-4 than among tumor grades 1-2. End
othelial cell hyperplasia was more frequent in nodular growth pattern, but
it did not correlate with survival. The highest capillary density was found
in nodular growth pattern, but it did not correlate with survival as well.
Microvascular proliferations correlated with survival only in univariate,
but not in multivariate analysis. Age, extent of surgical removal, year of
surgery, post-operative Karnofsky score and MIB-1 LI remained associated wi
th survival, as observed in a previous study.