Hemangioblastoma

43-year-old male with new onset seizure activity. There is a well circumscribed, rounded, T1 hypointense, non-diffusion restricting lesion within the posteromedial right cerebellar hemisphere and vermis with a rim of T2/FLAIR hyperintense signal and an enhancing mural nodule. The nodule abuts the underlying dural surface. There is moderate localized mass effect with partial effacement of the fourth ventricle. The differential includes hemangioblastoma, metastatic disease, pilocytic astrocytoma or ependymoma. This lesion was surgerized and proven to be a hemangioblastoma. Greater than 50% of hemangioblastomas present as a cyst with a mural nodule with less than 50% presenting as a solid mass. The fluid within the cyst component tends to be slightly hyperintense when compared to the surrounding extra-axial CSF space.