Where is this tumour located?
The tumour has a bilobed appearance and extends across the foramen of Luschka with components in the fourth ventricle and the left cerebropontine angle. The tumour extends anterior to the brainstem, along the clivus and just into the left IAM.
What imaging characteristics make this diagnosis the most likely?
Of the four commonest posterior fossa tumours, the ependymoma is the tumour most likely to exude from the fourth ventricle (where it arises) through the adjacent foramina.
Large posterior fossa tumour centred in the fourth ventricle and extending out of the left foramen of Luschka. It extends anterior to the brainstem and also just into the left IAM.