PROLIFERATIVE ACTIVITY OF CENTRAL NEUROCYTOMA - MEASUREMENT OF TUMOR VOLUME DOUBLING TIME, MIB-1 STAINING INDEX AND BROMODEOXYURIDINE LABELING INDEX

Central neurocytoma is considered to be a benign intracranial neoplasm , but little is known about the biological behavior of this type of tu mor. Proliferative activity of central neurocytoma was measured in 10 cases using MIB-1 staining for Ki-67 antigen. The MIB-1 staining value varied from < 0.1% to 5.6%, to indicating that some of these tumors h ave proliferative potential similar to that of anaplastic astrocytoma or malignant meningioma. The bromodeoxyuridine labeling index (BUdR LI , BrdU LI) was measured in 2 cases and the results correlated well wit h those of the MIB-1 analysis. Tumor volume doubling time (Td) measure d in one case was 358 days which is similar to that of malignant menin gioma. In one case, the MIB-1 value taken before and after 58 Gy of ra diation treatment decreased markedly from 5.6% to 0.2%. The other 9 ca ses were also treated by radiation therapy (50-60 Gy) and no tumor rec urrence was observed during follow-up periods ranging from 23 to 160 m onths. Another two patients with partially removed and 3 with subtotal ly removed tumors showing relatively high MIB-1 values might also have benefited from radiation therapy.