Is craniopharyngioma cancer? Symptoms, treatment, outlook

Craniopharyngioma is not cancer in the usual sense. It is a benign tumor, classified as grade 1 (the lowest grade) by the World Health Organization, and it does not spread to other parts of the body. It can still cause serious problems, because it grows in a crowded area at the base of the brain and can damage the pituitary gland, the hypothalamus and the nerves that carry vision.

What is craniopharyngioma?

A craniopharyngioma is a slow-growing tumor that forms near the pituitary gland, usually just above it. It is thought to develop from leftover cells of a structure that helps form the pituitary gland before birth.

Many craniopharyngiomas are partly solid and partly filled with fluid (cysts), and many contain calcium deposits that show up on scans. There are two main types:

• Adamantinomatous craniopharyngioma. The more common type, seen in children and adults. It is linked to changes in a gene called CTNNB1.
• Papillary craniopharyngioma. Found almost entirely in adults. Most of these tumors carry a change in the BRAF gene known as BRAF V600E, which matters because there are medicines that target it.

Is craniopharyngioma cancer?

No. Craniopharyngioma is classified as benign, meaning it does not invade distant organs or spread through the bloodstream the way cancers do. Doctors sometimes describe it as "histologically benign but clinically aggressive."

That phrase reflects the real challenge. The tumor can stick tightly to the hypothalamus, the optic nerves and major blood vessels. Removing it completely can risk damage to those structures, while leaving some behind raises the chance that it grows back. So even though it is not cancer, it is often treated by the same kinds of specialists who treat brain cancers, including neurosurgeons and radiation oncologists.

How rare is craniopharyngioma?

Craniopharyngioma is rare. A figure of roughly 1 to 2 new cases per million people per year is widely cited. It makes up only a small share of all brain tumors, although it is one of the more common tumors in this location in children.

Can craniopharyngioma occur in adults?

Yes. Craniopharyngioma has two age peaks: one in childhood and one in older adults, often in middle age and beyond. Adults can have either type, while the papillary type is seen almost only in adults.

What are the symptoms of craniopharyngioma?

Symptoms usually come from the tumor pressing on nearby structures, and they often develop slowly over months or years. Common symptoms include:

• Headaches, sometimes with nausea or vomiting if the tumor blocks the flow of fluid in the brain (hydrocephalus).
• Vision problems, such as loss of side vision or blurred vision, because the tumor sits close to the optic nerves.
• Hormone problems from pressure on the pituitary gland: tiredness, feeling cold, low sex drive, irregular periods, or delayed puberty.
• Slow growth in children, which is sometimes the first sign.
• Excessive thirst and urination, a sign of diabetes insipidus.
• Weight gain and changes in appetite, sleep or mood when the hypothalamus is involved.

None of these symptoms on their own means someone has a craniopharyngioma. Most have far more common causes.

Can craniopharyngioma cause diabetes insipidus?

Yes. Diabetes insipidus is a condition where the body does not make enough of the hormone that tells the kidneys to hold on to water, so a person passes large amounts of dilute urine and feels very thirsty. It can be present before treatment, and it is even more common after surgery, because the tumor often sits on the part of the brain that makes and releases this hormone.

After surgery it may be temporary or permanent. For more on how this is monitored and treated, see diabetes insipidus after pituitary surgery.

How is craniopharyngioma treated?

Treatment is planned by a team, and the right approach depends on the tumor's size, location, type, the patient's age, and how much the tumor involves the hypothalamus. The main options are:

• Surgery. Often the first step. Surgeons may operate through an opening in the skull (craniotomy) or through the nose using an endoscope, called the endoscopic endonasal approach.
• Radiation therapy. Commonly used after partial removal to lower the chance of regrowth. Options include conventional radiation, proton therapy and focused radiosurgery for small residual tumors.
• Cyst drainage. A tube and small reservoir can be placed to drain a large cyst and relieve pressure.
• Targeted medicine. For papillary tumors with the BRAF V600E change, drugs that block this pathway have shrunk tumors in studies and are increasingly used, often in clinical trials.
• Hormone replacement. Many patients need long-term replacement of pituitary hormones after treatment.

A key decision is how much of the tumor to remove. Taking out everything visible gives the best chance of preventing regrowth, but if the tumor is stuck to the hypothalamus, an aggressive operation can cause lasting problems with weight, sleep, memory and hormones. Many teams now favor removing as much as is safe and using radiation for what remains. The extent of resection is one of the most important factors in both outcomes.

Can craniopharyngioma be cured?

Craniopharyngioma can be cured in some patients, especially when the whole tumor can be removed safely. For others, the goal is long-term control: keeping the tumor from growing and protecting vision and hormone function.

Long-term survival is generally good. The bigger challenge for many families is quality of life after treatment, including hormone replacement, vision and, in some patients, weight gain and other effects of hypothalamic injury.

Can craniopharyngioma grow back?

Yes, craniopharyngioma can grow back, and recurrence is one of the main concerns after treatment. Studies have consistently found that regrowth is less likely after complete removal, and more likely after partial removal unless radiation follows.

Recurrence can happen years after treatment, so patients usually have regular MRI scans for a long time. A tumor that grows back can often be treated again with surgery, radiation or both.

Craniopharyngioma vs pituitary adenoma: what is the difference?

Both tumors are usually benign and grow in the same region, so they can cause similar symptoms. They differ in where they start and how they behave.

	Craniopharyngioma	Pituitary adenoma
Where it starts	Leftover developmental cells near the pituitary, often above it	Cells of the pituitary gland itself
How common	Rare	Common
Typical age	Children and older adults	Mostly adults
On scans	Often cysts and calcium deposits	Usually solid, rarely calcified
Hormones	Usually causes hormone deficiency	Can overproduce hormones or cause deficiency
Diabetes insipidus before surgery	Relatively common	Uncommon

Imaging, blood tests and sometimes tissue from surgery are used to tell them apart.

Some research tools now estimate an individual patient's risk of recurrence and permanent diabetes insipidus, such as this craniopharyngioma outcomes model. Decisions about treatment always depend on the individual and their care team.

Frequently asked questions

Can you die from craniopharyngioma?

Most people with craniopharyngioma live for many years after treatment. However, studies have found that long-term mortality is higher than in the general population, mostly because of complications such as hormone deficiencies, hypothalamic damage and heart and metabolic problems rather than the tumor spreading. Careful lifelong follow-up and hormone replacement help reduce these risks.

Is craniopharyngioma hereditary?

Craniopharyngioma is not generally considered an inherited condition. The gene changes found in these tumors (CTNNB1 and BRAF) arise in the tumor cells themselves rather than being passed down in families.

What kind of doctor treats craniopharyngioma?

Care is usually shared by a neurosurgeon, an endocrinologist (hormone specialist), an ophthalmologist or neuro-ophthalmologist for vision, and often a radiation oncologist. Children are usually treated at centers with pediatric neurosurgery and pediatric endocrinology.

Will I need hormone replacement after treatment?

Many patients do. Damage to the pituitary gland or hypothalamus, from the tumor or from treatment, often means replacing hormones such as cortisol, thyroid hormone, sex hormones, growth hormone and the water-balancing hormone. An endocrinologist adjusts these over time.