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| Axial Flair shows nodular masses in bilateral atria of lateral ventricles, non enhancing on post contrast T1 with typical restricted diffusion on Dw images suggestive of Choroid Plexus Cysts. |
A non neoplastic, non inflammatory cysts of choroid plexus lined by compressed connective tissue found at both ends of age spectrum.
o Adult: CPC is common incidental finding on imaging studies in older patients (approximately
40% prevalence)
o Fetus: CPCs seen in 1% of second trimester pregnancies.
Best diagnostic clue on imaging:
o Older patient with nodular cystic or nodular partially cystic masses on MRI with restricted diffusion.
o Fetus or newborn with large (> 2 mm) choroid plexus cysts on Antenatal Usg.
Location : Atria of lateral ventricles most common site. Usually bilateral.
Size: Variable, Usually 2-8 mm. Rarely large > 2 cm.
On CT
NECT
o Iso- or slightly hyperdense compared to CSF
o Irregular, peripheral Ca++ in majority of adult cases
CECT: Varies from none to rim or solid enhancement.
On MRI
• T1WI: Iso/slightly hyperintense compared to CSF
• T2WI: Hyperintense compared to CSF
• PD/lntermediate: Hyperintense
• FLAIR: 2/3rd iso-, 1/3rd hypointense on FLAIR
• T2* GRE: Blooms with intracystic hemorrhage (rare)
• DWI: 65% show restricted diffusion (high signal)
• Tl C+
o Enhancement varies from none to strong
o Variable pattern (solid, ring, nodular)
o Delayed scans may show filling in of contrast within cysts.
Differential Diagnosis
Ependymal cyst
• Doesn't enhance
• Usually unilateral
• Attenuation, signal more like CSF
Neoplasm
• Choroid plexus papilloma (children < 10 y; strong relatively uniform enhancement; cystic variant reported but rare)
• Meningioma (usually solid)
• Metastasis (rarely cystic)
• Cystic astrocytoma (rare in older patients)
Pathogenesis
Lipid from desquamating, degenerating choroid epithelium accumulates in choroid plexus - Lipid provokes xanthomatous response and result in Choroid plexus cysts formation.
Clinical presentation
Mostly asymptomatic, discovered incidentally at imaging
Rarely headache.
Age, prevalence increases with age.
No gender preponderance.
Reference : Diagnostic imaging Osborn.
