A study of CSF cells by 3H-thymidine autoradiography and cytology regarding the subarachnoid dissemination of brain tumor.

Abstract

In order to evaluate subarachnoid dissemination of brain tumor, the cerebrospinal fluid (CSF) cells of 104 patients with brain tumor were examined by 3H-thymidine autoradiography and cytology. As a control CSF cells from 34 patients with non-neoplastic disease were examined by the same method. Immediately after withdrawal by lumbar or ventricular puncture, the CSF was incubated with an admixture of 3H-thymidine at a concentration of 1–2 μCi/ml CSF at 37°C for 1 h. The CSF cells were collected by sedimentation or centrifugation and the microautoradiographic procedure was performed. The labeling index (LI) of CSF cells was counted excluding small lymphocytes and polymorphonuclear leukocytes. Labeled CSF cells were found in 33 of 34 cases of non-neoplastic cases. The mean LI of CSF cells in non-neoplastic cases was 0.4% and the highest was 1.7%. Cytological study revealed neoplastic CSF cells in 15 of 104 cases of brain tumor. A LI exceeding 1.7%, which was the highest in non-neoplastic cases, was encountered in 24 of 104 neoplastic cases. The highest LI in neoplastic cases was 14.4% in a case of primary reticulum cell sarcoma of the brain. High labelings were seen in cases of primary brain sarcoma, metastatic carcinoma, meningeal leukemia and pinealoma. In cases of glioma, even though malignant, the LI was relatively low in most cases. High LIs were parallel with the result of cytology in most cases. It was suggested that either 3H-thymidine autoradiography or cytology of CSF cells alone was not always conclusive for the diagnosis of subarachnoid dissemination of brain tumor, but by using both methods the diagnosis would be obtained with more accuracy.