Arachnoid Cysts in Children

An arachnoid cyst is a collection of benign fluid in the tissue between the skull and brain. Many children with this condition don’t have any symptoms and don’t need treatment.

For the children who do need treatment, our renowned pediatric neurosurgeons, at Children's Health℠, are national experts in arachnoid cysts and use the latest surgical treatments.

What is an Arachnoid Cyst?

An arachnoid cyst is a type of brain cyst (fluid-filled sac) that occurs in the tissue between the skull and brain. The fluid in the cyst is normal brain fluid, and it’s not cancerous. Most arachnoid cysts are congenital, meaning a baby has the arachnoid cyst when they’re born.

These cysts can range in size. Most small cysts don’t cause any symptoms or need treatment. Some arachnoid cysts enlarge shortly after birth, and large cysts can put pressure on the brain and may require surgical treatment.

What are the signs and symptoms of an Arachnoid Cyst?

The signs and symptoms of arachnoid cysts vary based on the child’s age and the size and location of the cyst. The signs and symptoms may include:

Rarely, arachnoid cysts can rupture with head trauma, which causes acute headaches and requires emergency medical attention.

How is an Arachnoid Cyst diagnosed?

Doctors diagnose arachnoid cysts with scans that allow them to see images of the brain and skull. This may include:

What causes an Arachnoid Cyst?

No one knows the exact cause of arachnoid cysts, but most arachnoid cysts are thought to be congenital, which means that a baby has had the condition since birth. Some arachnoid cysts are caused by scar tissue from a head injury or infection.

How is an Arachnoid Cyst treated?

Each child is unique, and recommendations for treatment are individualized based on the location and size of the cyst as well as the child’s age. Our renowned pediatric neurosurgeons are national experts in arachnoid cysts and we treat the most children with this condition in our region. That means our team is highly experienced in choosing the best treatment for each child and keeping the number of surgeries, risks and side effects to an absolute minimum.

Some children will need surgery to treat their arachnoid cyst, while many children won’t need any treatment.


For children who need surgery, there are two types of surgical treatments. Both treatments drain fluid, relieve pressure on the brain and keep fluids from reaccumulating.


Your neurosurgeon may recommend a treatment called fenestration. In this procedure, neurosurgeons make openings in the cyst wall to allow fluid to drain into the normal fluid pathways in the body. This can be done either endoscopically (using a long, thin tube) or through microsurgery (using a microscope).


The other surgical treatment is called a shunt. In a shunt procedure, neurosurgeons insert a shunt (thin tube) in the cyst, and the shunt diverts the fluid to the abdomen where it is absorbed into the body. The shunt stays in place after the surgery.

Arachnoid Cyst doctors and providers

Our pediatric neurosurgeons are national experts in arachnoid cysts and we treat the most children with this condition in our region.

Frequently Asked Questions

  • If my child receives surgical treatment, what will their recovery be like?

    They will spend some time recovering in the hospital after the procedure. Most children recover in a regular hospital room on the neuro-floor. Sometimes children spend one night in the PICU after their procedure before moving to a regular hospital room.

    Once they’re home from the hospital, they’ll continue to see their neurosurgeon for regular checkups to ensure they’re recovering well. Most children are able to return to their regular activities within a few weeks after treatment.