[The interest of CSF examinations in the etiological diagnosis of intracranial hypertension (author's transl)].

The authors discuss the case of a 15-year-old girl suffering from intra-cranial hypertension. Neuroradiological examinations do not reveal any obstruction in the cerebral spinal fluid circulation. The CSF cylologic examination was the first to give etiological indications, showing the existence of malignant cells which the cerebral biopsy later enabled us to classify as glioblastoma. This case affords an opportunity to recall the three stages of the diagnosis: first, intra-cranial hypertension; secondly, chronic meningitis; thirdly, cytological difficulties in the examination of CSF in patients having undergone neuro-radiological examinations.