Cytology of neoplastic meningosis.

Where a leptomeningeal carcinomatosis is clinically diagnosed, evidence should be provided of tumor cells in the CSF. Not necessarily in the first specimen, but in the course of the illness. The staining of the cells with the Pappenheim method generally provides sufficient information about the cells. The identification of cells in metastases of epithelial tumours is not difficult for anyone with some experience. Identifying cells from primary brain tumours - which however only rarely cause meningosis - can sometimes be more difficult. Attention should be paid to whether the cells occur in clusters or singly. However, extreme caution is called for. The cytological monitoring of the CSF is an essential part of chemotherapy or radiation treatment.