Although this is pedantic, when should the term cavum velum interpositum cyst be used rather than merely cavum velum interpositum?
When it is larger than 1 cm in the axial plane, with outwardly bowed margins and positive mass effect, the term cyst of the velum interpositum or cavum velum interpositum cyst should be used.
What is the management of these lesions?
In the vast majority of cases patients are asymptomatic. In cases where cystic dilatation is present with positive mass effect and obstruction to normal CSF flow, surgical (endoscopic) fenestration may be curative.
The cavum velum interpositum ( * ) is a triangular space in axial section located below the fornices (green) and above the internal cerebral veins (blue) and thus also above the pineal gland (yellow).