Primary diffuse leptomeningeal gliomatosis with signs of increased intracranial pressure and progressive meningeal enhancement on MRI.

A 21-year-old woman presented with a 5-month history of meningeal signs and evidence of intracranial hypertension and, as shown by magnetic resonance imaging (MRI), progressively more extensive meningeal enhancement, particularly within the spinal canal. Autopsy disclosed the presence of primary diffuse leptomeningeal gliomatosis with spinal cord predominance, possibly arising within heterotopic leptomeningeal glial tissue in the cervical region. No parenchymal primary lesion was identified. MRI with gadolinium appears to be the imaging modality of choice for the early detection of primary diffuse leptomeningeal neoplasia.