Etiology: Tumor involving the meninges which often does not have a parenchymal component
Imaging MRI: — Often there is no dominant primary parenchymal brain mass — T1WI post contrast: Diffuse thick nodular leptomeningeal thickening and enhancement particularly around the basilar cisterns and extending over the surface of the brain and spinal cord
DDX:
Complications:
Treatment:
Clinical: — Presents with hydrocephalus due to accumulation of tumor in subarachnoid space — Rare tumor
Radiology Cases of Diffuse Leptomeningeal Glioneuronal Tumor
Sagittal T1 MRI without contrast of the spine (above left) shows a focal protruberant intramedullary mass in the spinal cord at C7 and T1 that is hyperintense on sagittal T2 MRI (above center) and that on the sagittal T1 MRI with contrast (above right) enhances minimally. There is also thick leptomeningeal enhancement anterior and posterior to the cervical spine. The sagittal T1 MRI with contrast of the brain (below) shows thick leptomeningeal enhancement of the brain, particularly around the basal cisterns.Axial and coronal FLAIR MRI (left) show a bubbly cortical based lesion in the posterior medial right temporal lobe surrounded by some edema which on axial T2 MRI (above right) is seen to have a cystic component. Coronal T1 MRI with contrast (below right) shows diffuse leptomeningeal enhancement in the region around the lesion.
