The American Brain Tumor Association explains that while brain cysts are not cancerous, they can be found in cancerous tumors. Brain cysts can contain fluid, such as blood, cerebrospinal fluid, tissue or minerals. Leaking cysts can irritate nearby brain tissue. If the brain cyst causes problems for the patient, the doctor will treat it.
Multiple types of brain cysts exist. The colloid cyst, also called a neuroepithelial cyst, forms in the third ventricle in the brain and can block the flow of cerebrospinal fluid. As a result, patients with a colloid cyst can develop hydrocephalus, a buildup of cerebrospinal fluid in the brain, which results in increased intracranial pressure. The Chicago Institute of Neurosurgery and Neuroresearch explains that an arachnoid cyst, also called a leptomeningeal cyst, forms at birth. The epidermoid cyst, or cholesteatoma, occurs in middle-aged adults and forms from the cells that later become the skin. Patients with an epidermoid cyst have them in an area of the brain called the cerebello-pontine angle. Dermatoid cysts form of the same cells as epidermoid cysts. This type of brain cyst occurs in children. The Rathke's cleft cyst, which is found in the pituitary gland, can put pressure on the optic nerve and pituitary gland. Patients with this type of brain cyst can have vision problems and a loss of pituitary function. The American Brain Tumor Association adds that a pineal cyst, whose development is unclear, can cause headaches and hydrocephalus.
Treatment depends on whether the growth in the brain is a cyst or a tumor. The American Brain Tumor Association notes that if the scan, a MRI or a CT scan, shows a solid mass in the growth, then it is a brain tumor. If the scan does not show those components in the growth, then the patient has a cyst.
Sometimes, doctors may suggest waiting before treating a brain cyst. The Chicago Institute of Neurosurgery and Neuroresearch explains that the doctors will observe the cyst using scans in which they will look for changes in size. Examples of brain cysts that doctors may observe before treating include arachnoid cysts and pineal cysts. If the cyst does not cause symptoms or grow, doctors may determine that the patient does not need treatment. For some patients, the surgical options may have a bigger risk than waiting and watching.
The treatment options depend on the type of brain cyst. For example, the Chicago Institute of Neurosurgery and Neuroresearch points out that patients with an arachnoid cyst or colloid cyst may have a shunt installed, which drains the extra fluid in the brain. Less invasive surgical options exist for colloid cysts, such as a stereotactic aspiration and endoscopic aspiration. Surgical removal is an option for brain cysts, in which the surgeon creates an opening in the skull to reach the cyst and remove it. The American Brain Tumor Association adds that brain cysts association with a tumor may require radiation or chemotherapy.
The American Brain Tumor Association points out that if the treatment fully removes the cyst's wall, the risk of regrowth is low. The risk of regrowth increases if the treatment leaves part of the cyst's wall, even if the brain cyst was drained.