CHOROID PLEXUS NEOPLASMS
 

Sagittal Gd Enhanced T1W MR	Axial Gd Enhanced T1W MR

- Choroid Plexus Papilloma (WHO Grade I)

- Choroid Plexus Carcinoma (WHO Grade III-IV)

Cell of Origin: Choroid plexus epithelium

Common Locations:

Adults - Fourth ventricle

Children - Lateral ventricle

Demographics: Children > Adults. 40-50% papillomas seen in first year of life, 85% < 5 yrs. Carcinomas usually seen only in pediatric age group.

Clinical Presentation: Hydrocephalus

Histology: Papillomas have characteristic lobulated gross appearance. Most are well-differentiated and may resemble normal choroid plexus, however, anaplastic transformation may occur. Parenchymal invasion suggests carcinoma, but can be seen with benign .

Special Stains: Cytokeratin distinguishes from ependymoma; Prealbumin (transthyretin) may be helpful (although metastases may also stain positive)

Progression: CSF seeding may occur in both papillomas and carcinomas.

Radiology: Well-demarcated intraventricular (or cerebellopontine angle) mass with hydrocephalus. Calcification especially frequent in fourth ventricular tumors. In adult patients the fourth ventricle is more common. The tumor is attached to the choroid plexus.

Comments: Hydrocephalus may reflect multiple factors, including CSF over-production, ventricular obstruction, and impaired CSF reabsorption. Can present as a congenital neoplasm.