Craniopharyngioma, from the CureRays guide library.

Craniopharyngioma is a noncancerous but troublesome brain tumor near the pituitary gland and optic nerves; precise radiation, often after limited surgery, controls it while protecting vision and hormones.

What it is.

Craniopharyngioma is a rare tumor that grows near the base of the brain, close to the pituitary gland, the optic nerves, and the hypothalamus — a small but vital area that controls hormones, growth, appetite, and the body's internal balance. Although craniopharyngioma is not cancer in the usual sense (it does not spread to other parts of the body), it behaves like a serious problem because of its location: as it grows, it can press on the optic nerves and harm vision, disrupt the pituitary gland and cause hormone problems, and block the flow of cerebrospinal fluid and raise pressure in the head. It occurs in two peaks — in children and again in older adults — and can contain a mix of solid tumor and fluid-filled cysts that can enlarge. Symptoms often include headaches, vision changes, slowed growth or delayed puberty in children, excessive thirst and urination, and fatigue from hormone deficiencies. Because the tumor sits among such delicate and important structures, the central challenge of treatment is to control it while protecting vision, hormones, memory, and quality of life. Trying to remove every last bit of tumor can sometimes cause more harm than the tumor itself, so modern care often pairs a more limited surgery with precise radiation. The team typically includes neurosurgeons, radiation oncologists, and endocrinologists who manage hormone replacement, with long-term follow-up because the tumor can recur years later.

How radiation treats it.

Radiation therapy uses focused high-energy beams to damage the DNA inside tumor cells so they can no longer grow and divide. Although craniopharyngioma is not a cancer that spreads, it sits in one of the most delicate neighborhoods in the body — surrounded by the optic nerves that carry vision, the pituitary gland and hypothalamus that control hormones, and the pathways of memory. This is exactly why radiation is so valuable here. Trying to surgically remove every last piece of a craniopharyngioma that is stuck to these structures can cause lasting harm to vision, hormones, or memory. Modern radiation offers a gentler path: after a limited surgery removes the bulk of the tumor and relieves pressure, precise radiation controls whatever remains, dramatically lowering the chance of regrowth while protecting surrounding tissue. The dose is usually given in small daily treatments over several weeks (fractionation), which allows healthy structures like the optic nerves to tolerate it well, and it is shaped tightly around the target using intensity-modulated radiation, stereotactic techniques, or proton therapy. Protons are especially useful in children because the beam stops at a set depth, sparing the rest of the developing brain. One thing the team watches closely during radiation is the tumor's cysts, which can enlarge during treatment and may need to be drained so the radiation stays accurate. With careful planning, radiation achieves excellent long-term control of craniopharyngioma while preserving vision and quality of life as much as possible. Your radiation oncologist works alongside neurosurgeons and endocrinologists to balance tumor control with protection of these vital functions.

The ways we can treat it.

Intensity-modulated / fractionated radiation. Delivers radiation in small daily doses shaped tightly around the tumor over several weeks, controlling it while keeping the dose to the optic nerves, pituitary, and hypothalamus within safe limits.

Stereotactic radiosurgery. Delivers a high, precise dose in one or a few sessions to small, well-defined tumors set safely away from the optic nerves, a focused option for selected cases or recurrences.

Proton therapy. Proton beams stop at a controlled depth, sparing healthy brain beyond the tumor — particularly valuable in children to protect memory, thinking, and growth.

Intracystic treatment. For large cysts, a small catheter can drain the fluid or deliver treatment directly into the cyst, relieving pressure and reducing the tumor before or alongside external radiation.

Questions we hear often.

If craniopharyngioma isn't cancer, why is it treated so seriously? Even though it does not spread through the body, craniopharyngioma grows in a critical area next to the optic nerves, pituitary gland, and hypothalamus. As it grows it can damage vision, disrupt hormones, and raise pressure in the head, so controlling it is important to protect these vital functions.

Why not just remove the whole tumor with surgery? Craniopharyngiomas often stick to delicate structures that control vision and hormones. Trying to remove every last piece can cause more harm than the tumor itself. Modern care often pairs a more limited surgery with precise radiation, which controls the tumor while better protecting vision, hormones, and memory.

Will I need hormone treatment after radiation? Possibly. Because the tumor and its treatment can affect the pituitary gland, some people need hormone replacement — for example thyroid, cortisol, or growth hormone. An endocrinologist monitors hormone levels and replaces what the body needs to keep you healthy and balanced.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.