Assessment of proliferative potential in gliomatosis cerebri.

The proliferative potential of neoplastic cells in two cases of gliomatosis cerebri was investigated by a combined staining technique, a one-step silver colloid method for nucleolar organizer region-associated protein (AgNOR) and immunohistochemistry for fibrillary acidic protein (GFAP). The neoplastic cells in the two cases had an abnormal shape and showed positive GFAP immunostaining in their cytoplasm. The numbers of AgNORs were counted in central and peripheral lesions of the neoplastic field in each case. The mean AgNOR scores in neoplastic cells were almost the same as those of nonneoplastic astrocytes in both the central and the peripheral lesions. These values were almost equal to the AgNOR score of low-grade gliomas. These findings indicate that gliomatosis cerebri has an invasive character in the central nervous system and often shows a malignant tendency, but its proliferative potential is significantly lower than that of high-grade gliomas.