Presentation
Signs of raised intracranial pressure with obstructive hydrocephalus on CT (not shown). A VP shunt was inserted and an MRI was requested for characterisation.
Patient Data
Well-delineated lobulated cystic lesion centred on the pineal region of low signal on T1, heterogeneous/dirty signal on FLAIR and high signal on T2 with restricted diffusion and no enhancement on the postcontrast sequence. There is an extension to the superior cerebellar cistern with downwards displacement of the superior vermis. The midbrain and tectal plate are compressed and displaced anteriorly obliterating the aqueduct of Sylvius with dilatation of the 3rd and lateral ventricles and transependymal oedema.
The tip of the ventriculoperitoneal (VP) shunt is at the trigone of the left lateral ventricle with moderate dural thickening and enhancement.
Case Discussion
MRI features most consistent with an intracranial epidermoid cyst centred on the pineal region compressing and displacing the adjacents structures with obstructive hydrocephalus.