What is the differential for this lesion?
Central neurocytoma, ependymoma and subependymoma.
Which would you favour? Why?
Central neurocytoma should be strongly favoured. The mass does not enhance very much (ependymomas usually do) and the patient is a young adult (ependymomas tend to be in younger patients and subependymomas in older individuals). The imaging features are fairly typical of central neurocytomas.
A large mass located in the body of the right lateral ventricle, sending a tongue to tumour through the right foramen on Munro is present. It is lobulated with numerous cystic areas. The mass is of similar signal to white matter on T1 and T2 weighted sequences with restricted diffusion and speckled regions of susceptibility induced signal drop out. Following administration of contrast the mass only demonstrates faint heterogeneous enhancement.