Choroid plexus papilloma

Findings

CT images demonstrate a mildly hyper attenuating intraventricular lobular mass arising within the lateral body of the right lateral ventricle. There is associated ventriculomegaly, indicative of at least mild hydrocephalus.
MRI images confirm the presence of a well-delineated, lobulated mass in the right lateral ventricle. Mass is iso intense to gray matter on T1WI and demonstrates heterogeneous enhancement following gadolinium-DTPA. Bright periventricular signal on axial FLAIR images likely represents mild transependymal interstitial edema due to hydrocephalus.

Differential diagnosis:
- Choroid plexus papilloma/carcinoma
- Intraventricular meningioma
- Papillary ependymoma


Diagnosis: Choroid plexus papilloma (WHO Grade I)


Key points

Choroid plexus tumors (CPTs) are intraventricular, papillary neoplasms derived from choroid plexus epithelium
One of the more common supratentorial brain tumors in children less than 2 years of age; it represents the most common intraventricular neoplasm in children
86% present by 5 years of age
WHO grade I

Location:
- 70% of CPTs occur in the atrium of the lateral ventricle (L>R)
- 20% occur in the 4th ventricle (most common site of origin in adults)

Imaging findings:
- NECT: iso- or hyper attenuating intraventricular lobular mass
25% have calcifications
Hydrocephalus is common due to ventricular obstruction and/or CSF overproduction
- CECT: Intense, homogeneous enhancement
- MRI:
T1WI: iso- to hypo intense well-delineated, lobulated intraventricular mass
T2WI: iso- to hyper intense +/- internal linear and branching flow voids
FLAIR: Bright periventricular signal due to transependymal interstitial edema
T1WI+C: Robust homogeneous enhancement; cysts and small foci of necrosis may be present

May spread via subarachnoid space
May become anaplastic over time; imaging alone cannot reliably distinguish between choroid plexus papillomas and carcinomas
Treatment is total surgical resection (5 year survival close to 100%)