Presentation
Generalized body weakness for 3 days. No history of trauma.
Patient Data
A small lesion (extra-axial, intraventricular) is seen within the choroid plexus at the trigone of right lateral ventricle, measuring approximately 4mm. It has average attenuation number of -57HU.
Well defined hypodense foci are noted at the right frontal lobe, head of left caudate nucleus and left external capsule are suggestive of old lacunar infarcts.
Average attenuation number of this lesion is -57HU, in keeping with fat content.
Case Discussion
Choroid plexus lipomas are usually incidental findings when a CT scan is performed for another indication. Most patients are asymptomatic.
This case shows the importance of viewing the routine CT brain in other windows (such as soft tissue window- window width [WW] 400, window level [WL] 40) because the lesion does not stand out while viewing the CT scan in the usual brain window (WW 80, WL 40).
Measuring the attenuation number of this lesion is crucial for confirming fat content.
Using lung window, the lesion is not hypodense, indicating that this lesion is not an air pocket.