Craniopharyngioma

Craniopharyngioma is a rare, noncancerous brain tumor that develops near the pituitary gland, a pea-sized structure that controls many important body functions through hormones. Though these tumors grow slowly and don’t spread to other parts of the body, their location makes them serious because they can press on vital brain structures, affecting vision, hormone levels, and overall health.

Table of contents

• What is craniopharyngioma?
• Types of craniopharyngioma
• Who is affected?
• Signs and symptoms
• Causes
• How is it diagnosed?
• Treatment options
• Outlook and survival
• Living with craniopharyngioma

What is craniopharyngioma?

Craniopharyngioma is a rare type of noncancerous (also called benign) brain tumor that begins as a growth of cells near the brain’s pituitary gland^[1]. The pituitary gland is a small gland at the base of the brain that makes hormones controlling many body functions, including growth, metabolism, and reproduction^[1].

These tumors grow slowly and typically develop in the area near the pituitary gland called the sellar and suprasellar regions^[3]. As the tumor grows, it can affect the pituitary gland itself, the hypothalamus (another hormone-controlling structure), the optic chiasm (where the nerves from the eyes cross), the fluid-filled spaces in the brain called ventricles, and major blood vessels^[3].

• Pituitary gland
• Hypothalamus
• Optic chiasm
• Third ventricle
• Optic nerves

Although craniopharyngiomas are benign and do not spread to other parts of the body, they are considered serious medical conditions^[2]. Their location near delicate brain structures means they can cause devastating effects on vision, hormone function, and overall health^[10].

Types of craniopharyngioma

There are two distinct types of craniopharyngioma, each with different characteristics^[3]:

Adamantinomatous craniopharyngioma commonly affects children and can be found in all age groups. This type tends to be less solid and often has calcifications (calcium deposits) visible on imaging tests^[5]. These calcifications are hardened areas within the tumor that show up on X-rays and CT scans^[3].

Papillary craniopharyngioma is more prevalent in adults and is a more solid tumor. This type lacks calcifications and almost always occurs in adults rather than children^[5]. Some papillary craniopharyngiomas have changes in a gene called BRAF, which has opened up new treatment possibilities^[10].

Who is affected?

Craniopharyngioma is very rare. Approximately 2 people per 1 million are diagnosed with this tumor each year^[2]. In the United States, only about 600 people receive this diagnosis in a given year^[10].

These tumors typically present in two age groups: in children aged 5 to 14 and in adults aged 50 to 74^[2]. The adamantinomatous type can affect people of any age, while the papillary subtype is almost always found in adults^[2].

Craniopharyngioma can happen at any age, but it occurs most often in children and older adults^[1]. In adults, craniopharyngiomas account for less than 1 out of every 100 brain tumors^[7].

Signs and symptoms

The symptoms of craniopharyngioma are linked to pressure on the pituitary gland, hypothalamus, optic nerves, and brain. In children, growth and development problems may be more obvious than when a craniopharyngioma develops in an adult^[2].

Common signs and symptoms include^[1]:

• Headaches
• Vision changes
• Nausea and vomiting
• Increased urination
• Sleepiness
• Memory troubles
• Loss of balance
• Trouble walking
• Changes in personality or behavior
• Weight gain and slowed growth in children

Vision problems are particularly common because the optic nerves, which connect the eyes to the brain, are located above the pituitary gland^[2]. As the tumor grows, it can cause progressive loss of vision, particularly in the sides of the visual field (called peripheral vision)^[2].

The tumor can affect the pituitary gland’s ability to produce hormones, causing several hormone-related conditions^[2]:

Growth hormone deficiency affects children’s growth rates. Adults with this deficiency may have low energy, weak bones (osteoporosis), little muscle strength, and heart problems^[2].

Gonadotropin deficiency often causes delayed puberty in children. Women might not have menstrual periods, a condition known as amenorrhea^[2].

Adrenocorticotropic hormone (ACTH) deficiency causes people to feel weak and tired, along with weight loss, loss of appetite, muscle weakness, and nausea^[2].

Very large craniopharyngiomas can block the normal flow of cerebrospinal fluid (the clear fluid that surrounds the brain and spinal cord) in the brain. This can cause a buildup of fluid that increases pressure in the brain, a condition called hydrocephalus^[2]. Symptoms from increased pressure may include headaches (typically in the morning), nausea or vomiting (typically worse in the morning), and fatigue^[2].

Because these symptoms can be similar to other conditions, it can be difficult for healthcare providers to quickly conclude they are caused by this tumor^[2]. Symptoms can develop suddenly, making you feel unwell quickly, or they can develop more slowly over time^[7].

Causes

It’s not clear what causes craniopharyngioma^[1]. Craniopharyngioma happens when cells develop changes in their DNA. A cell’s DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA gives instructions for normal cell function and growth^[1].

The tumor arises from small nests of cells near the pituitary stalk^[5]. Scientists have identified specific genetic changes in the two types of craniopharyngioma. In adamantinomatous craniopharyngioma, the main pathway involves a protein called β-catenin and the WNT/Wingless pathway, which plays a critical role in cell development, growth, and movement^[9].

For papillary craniopharyngiomas, many tumors have changes in a gene called BRAF, specifically a change known as the BRAF V600E mutation. This discovery has led to new treatment approaches for this type^[10].

How is it diagnosed?

Diagnosing a craniopharyngioma usually starts with a medical history review and a discussion of symptoms^[13]. Tests used to diagnose craniopharyngioma include:

Neurological exam: During this exam, a healthcare professional tests vision, hearing, balance, coordination, reflexes, and growth and development. This can help show which part of the brain might be affected by the tumor^[13].

Blood tests: Blood tests may reveal changes in hormone levels that show a tumor is affecting the pituitary gland^[13]. These tests help check the levels of various hormones to see if the pituitary gland is working properly^[7].

Imaging tests: Imaging tests capture pictures of the brain and can show the size and location of the tumor. These include X-rays, CT scans (computed tomography scans), and MRI scans (magnetic resonance imaging)^[13]. MRI scans are particularly useful because they provide detailed images of soft tissues in the brain^[3].

Eye examinations: Because craniopharyngiomas often affect vision, eye tests are important to check for vision loss, particularly in peripheral vision^[5].

In certain situations, other tests might be needed^[13]. As well as finding out whether you have a tumor, the tests check the size of the tumor and its location, which helps your doctor plan treatment^[7].

Treatment options

The treatment of craniopharyngioma is complex and requires a team approach involving neurosurgeons, oncologists, endocrinologists (hormone specialists), and eye doctors^[3]. The main treatment options include surgery, radiation therapy, and in some cases, newer targeted therapies.

Surgery

Craniopharyngioma treatment often starts with surgery. When possible, surgeons remove all of the tumor. Sometimes the craniopharyngioma can’t be removed completely, so surgeons remove as much as is safe^[13].

Most people with craniopharyngioma have surgery to remove all or most of the tumor. What type of surgery you have depends on the location and size of the tumor^[13]:

Open craniopharyngioma surgery (also called a craniotomy) involves opening the skull to access the tumor^[13].

Minimally invasive craniopharyngioma surgery (also called a transsphenoidal approach) uses special tools and scopes that pass through the nasal passages^[13]. Because many craniopharyngiomas can be removed through the nose, this type of procedure does not require drilling into the skull or making facial or scalp incisions^[11].

The main problem that prevents complete removal is that craniopharyngiomas can be tightly attached to important structures such as the optic nerves, pituitary gland, and hypothalamus. Damaging these vital structures can lead to severe problems^[11].

If hydrocephalus (excess fluid in the brain) is present, a shunt (drainage system) may be placed during surgery to help remove excess fluid from the brain and ease the pressure^[5].

Radiation therapy

Radiation therapy may be used after surgery to treat any tumor cells that remain. Using surgery and radiation together often provides good tumor control and helps lower the risk of complications after surgery^[13].

If there is clearly some tumor remaining after surgery, or if there is doubt about whether any part of the tumor is left, then radiation is recommended to prevent the tumor from coming back^[11].

For small tumors, you might have stereotactic radiotherapy or radiosurgery, which target high doses of radiation precisely to the tumor^[7]. Some people may also have a type of radiotherapy called proton beam therapy, which uses high-energy proton beams to treat cancer^[7].

In children younger than three, radiation may be delayed by the use of surgery or hormone therapies because of concerns about radiation effects on the developing brain^[5].

Targeted therapy and chemotherapy

Other treatments, such as chemotherapy and targeted therapy, might be options in certain situations^[13]. Chemotherapy has emerged as an option for the papillary subtype of craniopharyngioma^[2].

People with tumors that have the BRAF mutation may benefit from targeted therapy^[5]. Recent research has shown that the combination of two targeted drugs, vemurafenib (Zelboraf) and cobimetinib (Cotellic), can substantially shrink tumors in people with papillary craniopharyngioma that has the BRAF V600E mutation^[10]. In one clinical trial, treatment with both drugs substantially shrank tumors in 15 of the 16 participants, and the tumors continued to respond for a median of 22 months^[10].

Hormone replacement therapy

Many people with a craniopharyngioma have changes in their hormone levels due to either the tumor itself or as a side effect of treatment. You might need to take hormone replacement therapy to help with this^[7].

To ensure the best outcome, an endocrinologist (a doctor trained to treat hormone imbalances) may work with the treatment team to develop a long-term care plan^[5]. The type of hormone you take depends on your individual needs^[7].

Outlook and survival

More than 90% of people with craniopharyngiomas are alive five years after diagnosis^[2]. This means that the survival rate for this condition is generally good compared to many other brain tumors.

However, craniopharyngiomas are treated as a chronic condition because treatment doesn’t always cure the conditions the tumors cause and because this kind of tumor often comes back (recurs)^[2]. About half of all surgically removed tumors come back over time^[2].

A craniopharyngioma is a serious medical condition that may require life-long medical treatment^[2]. Craniopharyngiomas cause several medical conditions that remain even after the tumor has been removed^[2].

Successful management is determined by the ability to preserve independent social functioning, prevent the tumor from coming back with symptoms, and increase survival rate^[9]. Problems with thinking and memory represent the major limiting factor for independent social functioning because patients often can overcome minor physical problems and hormone replacement therapies are widely available^[9].

Follow-up care

You have regular appointments with your doctor or nurse after treatment finishes. Your doctor examines you at each appointment, asks how you are feeling and whether you have had any symptoms or side effects, and you can discuss any worries you might have^[7].

You might have tests on some visits including tests to check your hormone levels, eye tests, and MRI scans^[7]. How often you have check-ups depends on your individual situation. Most people have a check-up every 6 to 12 months, for up to 5 years^[7].

Living with craniopharyngioma

Coping with a diagnosis of a brain tumor can be difficult, both practically and emotionally. It can be especially difficult when you have a rare tumor^[7]. Being well informed about the type of tumor you have, and its treatment can make it easier to cope^[7].

Many people with craniopharyngioma face ongoing challenges after treatment. These may include hormone imbalances that require lifelong medication, vision changes, weight management issues, and effects on memory or mood.

Support from family, friends, and healthcare providers is important. Many hospitals and organizations offer support groups where people with brain tumors and their families can share experiences and get advice from others facing similar challenges.

Regular follow-up with your medical team is essential to monitor for any signs that the tumor might be returning and to manage any ongoing health issues related to the tumor or its treatment. This typically involves working with several specialists, including neurosurgeons, endocrinologists, and eye doctors.

Despite the challenges, many people with craniopharyngioma live full and active lives with proper treatment and ongoing medical care.