Neuroradiology Board Review – Brain Tumors – Case 6
Neuroradiology brain tumor board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.
More description and the answer (spoiler!) are seen below the video.
This case shows images from an MRI of the posterior fossa. There is a mass in the right cerebellar hemisphere that has a predominantly cystic component and an enhancing nodule along the margin. There is some mass effect with effacement of the fourth ventricle.
The differential diagnosis for a posterior fossa cyst with a nodule has two main entities: pilocytic astrocytoma and hemangioblastoma. Pilocytic astrocytomas are the most common in children and young adults while hemangioblastomas are more common in adults. If you see flow voids on T2, that is also a nice clue that you are looking at a hemangioblastoma.
The diagnosis is: hemangioblastoma
Hemangioblastomas are cystic and solid masses that are commonly seen in the posterior fossa and spine. While they are often associated with von Hippel Lindau syndrome, the vast majority are sporadic (75-80%). They are usually cystic lesions with a solid nodule and minimal wall enhancement. Surgery can be curative, particularly if the entire enhancing nodule is resected, but it is not sufficient to drain the cystic component.
von Hippel Lindau is a syndrome of multiple lesions, with the most common in the kidneys (RCC, renal cysts, and angiomyolipomas). They are also associated with pancreatic cysts, adrenal pheochromocytomas, and other lesions. Think about this any time you see a CNS lesion with a corresponding abnormality elsewhere in the body.