Fig. 1

Radiological features. Pre-operative brain MRI a–f Images revealed a grossly well-marginated tumor mass lesion of approximately 8 × 9 cm located in the left parietal lobe. The lesion exerted severe mass effect on the ipsilateral lateral ventricle and adjacent brain parenchyma, resulting in contralateral active hydrocephalus (*in a and c) and midline shift. There was only mild peritumoral vasogenic edema. Signal intensity was strikingly heterogenous on all sequences suggesting the presence of core calcifications, necrosis and hemorrhage. The peripheral solid tumoral components displayed significant T2 prolongation (△ in a) and restricted diffusion on DW-images b, e and corresponding ADC map (△ in c), indicating high cellularity. ASL perfusion d demonstrated markedly increased CBF. Smaller size metastatic intraventricular (arrows in a–e), leptomeningeal (arrow in f) and parenchymal (bold arrows in e) lesions were present both supra-and infra-tentorially. The left parietal lobar lesion displayed faint, heterogenous contrast enhancement, whereas the right temporal lobe lesion enhanced avidly. The metastatic intraventricular deposits did not show any contrast uptake. Follow-up brain (g, h) and spinal cord (i) MRI: post contrast coronal T1-weighted (h) and sagittal T1-weighted (i) images of the brain and spinal cord, four weeks after diagnosis, demonstrated marked interval tumoral increase in size and progression of subependymal and leptomeningeal dissemination (arrows). Surrounding vasogenic edema was also increased (*in g). DW: diffusion-weighted; ADC, apparent diffusion coefficient; ASL, arterial spin labeling; CBF, cerebral blood flow