What is the most common mass found in the body of the lateral ventricle in patients over 40 years old?

Subependymoma is the most common mass in the body of the lateral ventricle in patients over 40. Key diagnostic features include a well-circumscribed, non-enhancing lesion often found incidentally on MRI. Clinically, these are typically asymptomatic but can cause hydrocephalus if large. A common pitfall is mistaking them for ependymomas or meningiomas, which usually enhance with contrast.