Figure 17.

Malignant schwannoma: a 51-year-old male presented with dizziness. Post gadolinium T1W image shows an enhancing left cerebellopontine angle mass (yellow arrow) with a cystic component (red arrow). The solid mass shows restricted diffusion (red circle) on DWI with a low ADC value (yellow circle), suggestive of a malignant mass, however the cystic component did not show any diffusion restriction. PET-CT showed the cystic component to be hypometabolic (black arrow) confirming the findings of DWI. This is a typical location and imaging behavior of malignant schwannoma. DWI: diffusion-weighted imaging; ADC: apparent diffusion coefficient; PET-CT; positron emission tomography computed tomography.