Causes & Risk Factors
Brain tumor
A brain tumor can cause hydrocephalus by blocking the flow of cerebrospinal fluid through the ventricular system.
In short: Brain tumor
- A tumor can obstruct CSF flow, causing obstructive hydrocephalus.
- Tumors near the CSF pathways are especially likely to do so.
- Treating the tumor can sometimes relieve the hydrocephalus.
- Temporary or permanent CSF diversion may also be needed.
What it is
A brain tumor is an abnormal growth of tissue in the brain. Depending on its location, a tumor can obstruct the flow of cerebrospinal fluid, causing obstructive hydrocephalus.
Understanding Brain tumor
Tumors located near the CSF pathways — such as in or around the ventricles, the cerebral aqueduct, or the posterior fossa — can press on or block the channels through which CSF flows, causing fluid to back up and the ventricles to enlarge. Treating the tumor (for example, by removing it) can sometimes relieve the obstruction and the hydrocephalus, but in some cases CSF diversion is also needed, either temporarily (such as an external ventricular drain) or permanently (a shunt or ETV). The approach depends on the tumor type, location, and the individual situation.
Why it matters
Understanding tumors as a cause helps families see how a growth near the CSF pathways can block fluid flow and cause hydrocephalus, and why both the tumor and the hydrocephalus may need to be addressed.
Common questions
How can a brain tumor cause hydrocephalus?
By blocking CSF flow through the ventricular system.
Which tumors are most likely to?
Those near the CSF pathways, such as in the posterior fossa.
Does treating the tumor fix the hydrocephalus?
Sometimes; CSF diversion may also be needed.
Bottom line
A brain tumor can cause obstructive hydrocephalus by blocking CSF flow, addressed by treating the tumor and, often, diverting CSF.
Browse all 265 Hydrocephalus definitions
Read the Hydrocephalus patient guides
Not sure which page you need? Put words to it with the symptom navigator