Presentation
Acute onset vertigo. Further characterization of lesion seen on CT.
Patient Data
There is a large pineal region mass, which is isointense to grey matter on T1 and slightly hyperintense on T2. There is a small cystic region in the inferior portion. The mass shows diffusion restriction, and vividly and homogeneously enhances. It has a broad attachment to the inferior margin of the falx cerebri, displacing the internal cerebral veins inferiorly and to the right, with mass effect and thinning of the splenium of the corpus callosum. There is no mass effect on the cerebral aqueduct and no hydrocephalus. A normal pineal gland cannot be identified. Normal enhancement of the straight sinus. This is a solitary lesion.
Case Discussion
Given the patient's age and lack of symptoms (vertigo was felt to be incidental to this mass), histology is not available for confirmation. This mass has all the characteristics of a meningioma, just in an uncommon position. Seeing a normal pineal gland would be further reassuring but this is unlikely to be pineal in origin because it displaces the internal cerebral veins inferiorly, whereas a pineal gland mass would displace the internal cerebral veins superiorly.