Overview

Craniopharyngiomas are a rare type of non-cancerous brain tumour that can disrupt mental and physical development. Through diagnosis and successful treatment, craniopharyngiomas can be managed to improve quality of life. By highlighting the process, this article aims to raise awareness of craniopharyngioma care.

What is a craniopharyngioma?

Craniopharyngiomas are a type of slow-growing tumour that develops near the base of the brain.¹ These can present as solid or fluid-filled sacs which grow close to the pituitary gland. This gland produces hormones that influence growth, metabolism and reproduction. There are two main types of craniopharyngioma:² 

• Adamantinomatous (ACP)
• Papillary (PCP)

ACPs can be found across all age groups, but are more common in children. On the other hand, PCPs are almost exclusively found in adults. Due to their close proximity to the pituitary gland and other nearby structures, both types tend to cause similar symptoms. 

Symptoms

As the craniopharyngioma grows, it starts to apply pressure on the surrounding structures of the brain. Given its close relation, symptoms of craniopharyngioma can be related to altered function of the pituitary gland. Some of these symptoms are:¹

• Growth deficiency 
• Feeling thirsty 
• Increased urination 

Craniopharyngiomas are also located near the optic chiasm,a central crossroads in the brain where the optic nerves meet. The optic nerves help your brain understand what your eyes are seeing. Rarely, the growth of a craniopharyngioma can apply pressure to the optic chiasm leading to problems with vision.³

How common are craniopharyngiomas?

In children diagnosed with brain tumours aged between 5-14 years, 6-10% will be diagnosed with a craniopharyngioma. In adults between the ages of 50-65 years, however, craniopharyngiomas account for less than 1% of brain tumours.^{1, 4}

Diagnosis

Diagnosis of craniopharyngioma can be challenging and begins with looking at your medical history. In the assessment of children, doctors will look for delayed growth and cognition as possible indicators of a craniopharyngioma. There are several tests that may be used together to diagnose a craniopharyngioma including testing your nerves (neurological examination), looking at blood markers and later arranging more detailed imaging (such as an MRI scan).⁵

Neurological examination 

A neurological exam involves different physical tests to assess brain function. Doctors may test your vision, sensation, coordination, balance and reflexes to narrow down where the tumour might be located in the brain.

Blood tests

Blood tests are commonly used to help diagnose craniopharyngiomas. Pressure applied to the pituitary gland, through the growth of this brain tumour, will alter hormone levels in the blood. Reduced levels of circulating growth hormone is a potential indicator of a craniopharyngioma.²

Imaging 

There are two main imaging techniques used to detect craniopharyngiomas: CT and MRI scans. 

MRI is the preferred method as it provides clear images for pinpointing the exact location of the craniopharyngioma. MRI also shows how the tumour interacts with surrounding structures, allowing surgeons to plan the best way to remove the tumour.² CT scans can also be used to detect craniopharyngiomas. Although a CT scan is quicker than an MRI, the images of the tumour are not always as clear.

Treatments 

There are several treatment options available for people affected by craniopharyngiomas. Surgery is usually the first course of action. This may or may not be followed up with radiotherapy or chemotherapy, depending on the results of the operation. 

Surgery 

Surgeons aim to remove as much of the tumour as possible generally using one of the following techniques:⁵ 

• Craniotomy: This is a type of open surgery where the surgeon removes and replaces part of the skull to access the tumour 
• Endoscopic surgery: This is a less invasive approach which involves inserting a small tube with a camera through the nose and into the brain to treat the tumour 

Due to craniopharyngiomas growing close to important brain structures, such as the optic chiasm and pituitary gland, it can be difficult to remove the tumour completely. Surgeons are wary of damaging surrounding structures while operating, therefore surgery is often paired with radiotherapy. 

Radiotherapy

Radiotherapy is a type of high-energy radiation that is directed towards a tumour to kill the cells, control its growth, or prevent it from coming back. Depending on the scenario, there are different types of specialised radiotherapy that can be used:⁵ 

• External beam radiotherapy 
• Stereotactic radiosurgery (SRS)
• Brachytherapy

Due to its intense nature, radiotherapy can also kill healthy cells often leading to unpleasant side effects, such as:⁶

• Feeling tired
• Nausea 
• Sore skin
• Hair loss in the treated area 

External beam radiotherapy

External beam radiotherapy directs rays of high energy towards tumour cells using a machine outside of the body. The beams of high energy are steered as much as possible to align with the shape and size of the craniopharyngioma and avoid damage to the surrounding healthy cells.⁷ 

Stereotactic radiosurgery 

Stereotactic radiosurgery involves directing multiple radiation beams towards the tumour from different angles around the head. This gives the craniopharyngioma a high dose of radiation in one go, so it normally only needs a single radiotherapy session. If multiple treatment sessions are required, this is known as fractionated stereotactic radiotherapy.⁸

Since stereotactic radiosurgery is highly precise, the surrounding healthy cells are less damaged in the process. As a result, there are fewer unpleasant side effects. 

Brachytherapy 

This is an alternative option to ‘beam-type radiotherapy’, where a small piece of radioactive material is temporarily inserted either inside or near the tumour. These radioactive materials can come in several forms, including seeds, discs or wires.⁹ 

This type of radiotherapy aims to kill tumour cells from the inside out and avoid damage to nearby cells.

Chemotherapy 

While radiotherapy is preferred as a second-line treatment for craniopharyngioma, following surgery, chemotherapy offers an alternative drug-based approach. 

Chemotherapy involves using strong medicine to kill cancer cells and prevent tumour growth. For craniopharyngioma, chemotherapy drugs are injected directly into the tumour to minimise damage to surrounding healthy cells.¹⁰ However, as with radiotherapy, the intensive nature of chemotherapy may cause you to experience side effects. 

What happens next?

Prognosis 

The outlook for craniopharyngioma treatment differs between individuals and depends on a number of factors, including the size of the tumour and the success of the surgery. 

When surgeons are unable to fully remove a craniopharyngioma, there is a 50% chance that the tumour will come back. Despite a high recurrence, the overall survival rate for people with a craniopharyngioma is between 80-95% at 5 years after treatment.²

Follow-up care 

After craniopharyngioma treatment, whether in the form of surgery, chemoradiotherapy, or both, it is important to schedule follow-up appointments with your healthcare team. 

Follow-up allows specialists to keep a close eye on your general health during your recovery. The team will be there to help you manage post-treatment side effects, as well as watch out for any signs of craniopharyngioma coming back. 

Regular check-ups are usually scheduled every 6-12 months for 5 years.¹¹ This may include outpatient MRI scans to see if the craniopharyngioma has grown, for example, if it wasn’t fully removed after surgery. 

Hormone replacement therapy

Craniopharyngiomas can alter hormone levels, whether through applying direct pressure on the pituitary gland or as a result of surgery. 

To counter this, individuals may need to take hormone replacement therapy. The specific type of medication will differ depending on the needs of the individual.¹¹

Summary 

Craniopharyngiomas are non-cancerous brain tumours that can alter the function of surrounding structures in the brain when they grow, leading to headaches, hormonal imbalances and problems with your vision. After detection, surgeons will most likely opt to remove the craniopharyngioma and follow up with radiotherapy to kill any remaining tumour cells. Post-treatment care is vital to track any side effects related to the treatment and monitor for signs of the craniopharyngioma returning.. Although the tumour can recur, the long-term outlook for patients with a craniopharyngioma is good. 

FAQs

Are craniopharyngiomas cancerous?

Craniopharyngiomas are not cancerous and do not spread. Despite being non-cancerous, they still can be dangerous due to their location close to important structures in the brain. 

Can craniopharyngiomas come back?

There is around a 50% chance that a craniopharyngioma will come back after treatment. Recurrence is closely monitored after treatment by your healthcare team through scheduled check-ups, which may involve blood tests or scans at certain intervals. 

Are there long-term side effects of craniopharyngioma treatment?

Both a craniopharyngioma and its treatment can impact your quality of life. There is a risk of damage to nearby brain structures during surgery which may lead to hormonal changes or visual loss. However, without treatment, a craniopharyngioma could eventually disrupt the function of the brain in similar ways – unfortunately leading to the same problems.