What’s the diagnosis?
- Abnormal communications between the intra- and extra-cranial venous systems are classically termed sinus pericranii.
- Sinus pericranii are usually congenital and seen in children. However, these venous anastomoses can rarely be acquired.
- Meningiomas commonly demonstrate intravenous extension and dural venous sinus occlusion due to meningiomatous invasion is a well known phenomenon.
- In this case, the most likely pathophysiology is that chronic meningiomatous invasion of the intracranial sinuses → venous outlet obstruction → venous hypertension → development of collateral outflow channels.