[An evaluation of cerebrospinal fluid cytology in childhood leukaemias and lymphomas (author's transl)].

A cytological study of the cerebrospinal fluid was carried out on 72 children with leukaemia or lymphoma either at the onset or during the course of the disease. It proved extremely useful in revealing the presence of malignant cells in CSF's with normal cell count and in distinguishing with absolute certainty meningeal leukaemias from meningeal reactions of other origins, in particular the frequent histiocytic reactions to radiotherapy and/or chemotherapy. These "irritative" reactions are a reminder that iatrogenic damage to the central nervous system is a distinct possibility, and the modalities of treatment should perhaps be reconsidered when they attain a certain magnitude.