An aggressive appearing tumour is seen on the pineal region / tectal plate / superior vermis. It measures 37 x 40 x 40 mm, is of slight increased signal intensity on T2 weighted images, with multiple areas of cystic change, and hypointense on T1, with strikingly restricted diffusion, and moderate enhancement of the non cystic components. It fills the tentorial incisura, displaces the tectal plate to the right and anteriorly, extends into the perimesencephalic cistern on the left, and into the medial aspect of the left occipital lobe towards the ependyma of the lateral ventricle. The tumour and displaced superior vermis of the cerebellum cannot be differentiated, indicating either invasion or origin from the cerebellum.
The internal cerebral veins are clearly seen immediately above the main
tumour mass as is the pineal galnd. The vein of Galen and straight
sinus elevated immediately above the mass appear patent.
There is mild hydrocephalus secondary to aqueduct compression with minimal transependymal oedema. Cerebral parenchymal signal intensity and architecture elsewhere normal. This no evidence of CSF spread of tumour in intracranial compartment beyond the main tumour mass.