Correlation of histopathological features and proliferative potential of gliomas

One hundred fifty-two intracranial gliomas of various types were reviewed in order to correlate the histopathological features with the proliferative potential of each tumor as reflected by the bromodeoxyuridine (BUdR) labeling index (LI). Patients undergoing surgical removal of gliomas were given a 30-iminute intravenous infusion of BUdR (150 to 200 mg/sq m) to label S-phase tumor cells. The tumor specimens were stained immunohistochemically for BUdR and processed for routine histopathological diagnosis. The BUdR LI was calculated as the percentage of labeled cells among cells analyzed. Twenty-seven histological features in three categories (degenerative, vascular, and cellular changes) were considered. A significantly higher BUdR LI (p < 0.05) was found in tumors with necrosis than in those without this feature; tumors with both coagulative and liquefactive necrosis had the highest BUdR LI (p < 0.05). Increased vascularity was also associated with a higher BUdR LI (p < 0.05). Although tumors with abnormal mitotic figures had a significantly higher BUdR LI than those without, the number of mitoses did not correlate with a higher BUdR LI. These results suggest that the number of mitoses is not a good indicator of tumor growth rate. Necrosis and increased vascularity should be heavily weighted in predicting the proliferative potential of individual gliomas.