Neuroradiology Board Review – Brain Tumors – Case 11
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 an MRI with mass along the left cerebral convexity. The mass is pretty homogeneous on all sequences. On pre- and post-contrast T1, there is pretty avid enhancement.
Anytime you are looking at a brain mass, you should try to decide if it is arising within the brain parenchyma (intraaxial) or outside the brain parenchyma (extraaxial). The main clue that a mass is extra-axial is if it displaces the adjacent brain and you can see a cleft of CSF between the tumor and the adjacent brain. The differential diagnosis for an extra-axial mass (meningioma, lymphoma, metastatic disease) is very different from the differential diagnosis for an intra-axial mass (glioma, metastasis, demyelinating disease, infection).
The diagnosis is: meningioma
Meningiomas are the most common brain tumors overall and the most common extra-axial tumors. They are usually homogeneous and can have avid enhancement. Nice clues are if you see a cleft of CSF between the mass and the brain and if you have dural tails (small enhancing components extending along the dura adjacent to the mass). Sometimes meningiomas have a radiating spoke pattern extending out from the calvarium.
Meningiomas can be WHO grade 1, 2, or 3. All grades are treated with resection. Since Grade 2 and 3 have a higher risk of recurrence, they are often treated with radiation after resection.
The ABR loves to add anatomy questions as a follow-up. In this video, I’ve shown you the hand knob, which is an “inverted omega” shaped gyrus in the precentral gyrus. This is a good clue that you are in front of the central sulcus and is a reliable way to identify the central sulcus.