Weekly Image Challenge – March 13, 2023

What is the most likely diagnosis on these MRIs of a 56-year-old lady?

  1. Choroid plexus carcinoma
  2. Trigone meningioma
  3. Ependymoma
  4. Metastasis
  5. Central neurocytoma


Congratulations to those who selected trigone meningioma. Intraventricular meningiomas are rare and are most commonly found at the trigone of the lateral ventricle (80%). Their appearance is the same as that of the dural-based meningioma: iso-intense on T1, hyper-intense on T2, and homogenously contrast enhancing, with limited or no cerebral edema.

Choroid plexus carcinoma is iso- to hypo-intense on T1 and T2 and has vivid but heterogeneous contrast enhancement. It occurs more commonly in childhood.

Ependymoma is a close differential with a nearly similar appearance. It is also more common in the younger population and can have cystic areas.

Metastasis is rarely intraventricular. It usually has a central necrotic core and surrounding edema.

Central neurocytoma typically arises from septum pellucidum and shows mild contrast enhancement if any. It is iso-intense on T1 and T2 images.