True or false: Colloid cysts are usually hyperdense on CT.
True. The vast majority are hyperdense.
How do these lesions present?
In the vast majority of cases, colloid cysts are found incidentally and are asymptomatic. Their position in the roof of the third ventricle immediately adjacent foramen of Monro can on occasion result in sudden obstructive hydrocephalus and can present with a thunderclap headache or unconscious collapse. The headaches tend to be positional, and patients may learn how to relieve symptoms.
How are colloid cysts treated?
If resection is required, this can be performed via a transcallosal approach or more recently endoscopically.
Colloid cyst (blue arrow) located just below the foramina of Monro (red arrows) which form a communication between the frontal horns of the lateral ventricles (FH) and the third ventricle (TV).