Finding out that your child has a brain cyst can be scary, especially since there may not be obvious signs that a problem exists. Most cysts are benign (non-cancerous) and many do not require treatment. Those that do require treatment are often minimally invasive and result in good outcomes.
A brain cyst is a balloon-like sphere found in the brain. The most common—the arachnoid cyst—is full of cerebrospinal fluid. Other types can contain pus, hair follicles or skin cells. They are not considered tumors, and are usually non-cancerous.
Arachnoid cysts get their name from the arachnoid membrane that makes up the cyst wall. They can occur in the brain or spinal canal. Arachnoid cysts affect approximately 3 in 100 people, but most will never know because they often go undetected.
Most arachnoid cysts are congenital, meaning they are present at birth. The exact cause of congenital arachnoid cysts is unknown, but there is evidence that some people have a genetic predisposition, meaning it is passed on through families. Rarely, complications from arachnoid cysts may develop due to a head injury, infection, surgery or the presence of a brain tumor.
Arachnoid cysts often have no symptoms and may go undetected for years if they remain small. When arachnoid cysts grow, they can apply pressure on the spinal cord, cranial nerve or brain, which may cause symptoms. Symptoms may include:
When symptoms do occur, they depend on the location and size of the arachnoid cyst and what brain regions it presses against, affecting function.
Many times, arachnoid cysts are found incidentally, when a child has a test such as an MRI or CT scan for another reason like head trauma.
While most cysts can be monitored clinically, there are times when the cyst grows and treatment becomes necessary. Because an arachnoid cyst is a fluid-filled sac, the goal in treatment is to fenestrate, or create very small openings, in the wall of the cyst so the fluid can drain into a location where they body has built-in abilities to re-absorb the fluid. This relieves the pressure that is created by the cyst, and alleviates symptoms.
Depending on the course of treatment, you will likely have follow-up visits with your child’s doctor at CHOC. CHOC will follow your child throughout their life, from birth to surgery to recovery and beyond, with regular checkups to ensure the best possible outcome for your child.
While a condition like an arachnoid cyst may be a new diagnosis for your child, it is familiar to us, and we have years of experience diagnosing and treating cases that range from common to complex. We also understand that each case is unique, and will develop an individual treatment plan just for your child and their needs.
Dr. Joffre Olaya specializes in neurosurgery. He sees kids and teens at CHOC Children's Hospital in Orange and CHOC Children's at Mission Hospital.
Dr. Michael Muhonen is a board certified neurosurgeon at CHOC Children's and serves as medical director of the CHOC Children's Neuroscience Institute.
Dr. William Loudon is a board-certified pediatric neurosurgeon at CHOC Children's.