Rapid detection of proliferating potential in human brain tumors by nucleolar organizer region staining on squash preparations.

Rapid detection of the proliferating potential of 37 human brain tumors was attempted using squash preparations stained by a silver colloid technique for argyrophilic protein associated with nucleolar organizer regions (AgNORs). Less than 1 h was required for staining. The mean number of AgNORs in cell nuclei of malignant or recurrent brain tumors (16 cases) including meningeal sarcoma, recurrent meningioma, recurrent craniopharyngioma, anaplastic astrocytoma, glioblastoma multiforme and metastatic brain tumor was 3.18, and the number for benign brain tumors (21 cases) including meningioma, neurinoma, pituitary adenoma, benign astrocytoma, ependymoma, and adenoma of lachrymal gland was 1.85. The former value was significantly greater than the latter value (P less than 0.001). These results indicate that quantitative analysis of AgNORs in brain neoplastic cells, using squash preparations, is useful to differentiate malignant from benign tumors within 1 h. Thus, this method provides rapid and useful information about the proliferative potential of human brain tumors even during operation.