[Cerebrospinal fluid cytological diagnosis of primary and metastatic tumours of the central nervous system (author's transl)].

In the routine cytological examination of the lumbar CSF of 4000 patients, the diagnosis of a tumour was made in 46 cases, most being metastases to the CNS, 20 having meningeal carcinomatosis. There were 9 malignant cerebral tumours of neuroepithelial origin, 2 spinal meningioma and 1 spinal neurinomas. Autochtonous cerebral tumours rarely exfoliate or become differentiated so are more difficult to identify and especially to distinguish from the nonspecific CSF irritation syndrome. On the other hand metastases are morphologically distuinguishable by cell type and the large number of mitoses. Cytological study of the CSF is of great diagnostic value and, in some cases is the only way to make the correct diagnosis.