Choroid plexus lipoma
Choroid plexus lipomas are uncommon and like other intracranial lipomas are usually found incidentally at the trigones of the lateral ventricles when imaging is obtained for other indications.
Terminology
Some of the literature refers to the extension of tubulonodular pericallosal lipoma into the choroid plexus within the bodies of the lateral ventricles as choroid plexus lipomas . Although this too is adipose tissue within the choroid plexus, it is distinct from small isolated lipomas in the choroid at the trigones of the lateral ventricles.
Epidemiology
In one study the prevalence of choroid plexus lipomas was found to be 0.45% . They can occur in all age groups.
Clinic presentation
Most patients are asymptomatic with the lesion being discovered incidentally .
Pathology
Choroid plexus lipomas are not true neoplasms but are rather a form of congenital malformation due to the persistence of the meninx primitiva . The lesions are typically solitary although may be bilateral in some cases.
Radiographic features
Ultrasound
Transcranial antenatal ultrasound may reveal a well defined hyperechoic mass .
CT
Choroid plexus lipomas may be found on CT. However, CT has been noted to have poor sensitivity for their detection presumably due to narrow window (brain window) setting of routine brain CT
MRI
MRI is much more sensitive for detecting choroid plexus lipomas. They are usually small rounded lesions between 2 mm to 1 cm in diameter located in the region of trigone of the lateral ventricle . They follow fat on all sequences and therefore have the following sequence characteristics :
- T1: high signal
- T1 C+ (Gd): non-enhancing
- T2: high signal
- fat saturation: lose signal
May exhibit chemical shift artefact.
Treatment and prognosis
These lesions are invariably asymptomatic and treatment is generally not required.
See also
