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British TV presenter Davina McCall has undergone neurosurgery to remove a colloid cyst – a type of benign brain tumour.
McCall was diagnosed with the tumour by chance. In an Instagram video posted in November 2024, she explained:
A few months ago, I did a menopause talk for a company and they offered me a health scan in return, which I thought I was going to ace. But it turned out I had a benign brain tumour called a colloid cyst, which is very rare – three in a million.
Colloid cysts are rare examples of fluid-filled cerebral tumours, which account for less than 1% of diagnosed brain tumours.
They develop in the ventricles – the fluid containing chamber system inside the brain – which produce cerebrospinal fluid (CSF). CSF is ultra-filtered blood which allows nutrients and important chemicals to circulate in and around the brain, and provides additional protection.
Normally, CSF passes back into the bloodstream, but different conditions – including tumours – can affect this. A growing tumour can obstruct CSF, so, instead of being able to pass back into the bloodstream, the fluid can start to accumulate inside the brain. This is called hydrocephalus – otherwise known as “water on the brain”.
Since the skull is like an immovable protective box, the build up of fluid raises the pressure inside the head. It’s this pressure increase that causes symptoms like headaches, nausea and vomiting.
But colloid cysts are not the only condition that can cause these symptoms. Other types of brain tumour can develop from neurones (nerve cells). Glial cells, which support and insulate neurones, can form more common brain tumours known as gliomas.
Even cells which aren’t part of the brain, but wrap around it for further protection, can transform into tumours. The layers of tissue known as the meninges (which get inflamed in meningitis) can turn into meningiomas. These can grow to significant sizes. They are considered “giant” if more than 5cm in diameter.
The largest brain tumour on record was 570g in mass, removed from a four year old boy in India in 2000.
Cerebral tumours are classified according to whether they are benign – growing, but not spreading – or malignant (cancerous), and capable of moving to other parts of the body. Some brain tumours can develop from the spread (metastasis) of cancers from other parts of the body. This occurs more commonly from the breast, lung, kidney, colon and skin.
Symptoms
It seems that McCall was symptom free; however, brain tumours can trigger noticeable symptoms – and recognising them early is critical.
Like all cancers, brain tumour prognoses vary according to the type of tumour – but also how much it has grown or spread when diagnosed. It’s important, then, to recognise cancers of any type as soon as possible to prevent progression.
Unfortunately, the symptoms associated with brain tumours are often non-specific. Nausea, vomiting and headaches are all commonplace symptoms. They can also be caused by many other conditions.
The most suspicious headaches are those that suggest increased pressure in the brain. These headaches tend to be worse when waking in the morning, changing posture, or when accompanied by vomiting. If you notice a headache like this – or one which is persistent, worsening or changing – and any of the other symptoms I’ve mentioned, then do contact your GP. Be reassured, though, that fewer than 1% of patients with a headache will actually have a brain tumour.
Brain tumours can cause other general symptoms, too, such as changes in vision, dizziness and new-onset seizures. In fact, one of the indicators for an urgent CT head scan is a first time epileptic seizure to check whether a tumour is the underlying cause for the fit.
Other symptoms depend on where a tumour is located – since it will interfere with the normal function of that brain region. For instance, if a tumour is located within the cerebellum at the back of the brain, the patient may find it difficult to walk steadily, or notice a tremor. This is because the cerebellum is responsible for controlling balance and fine tuning body movements. If a tumour develops in the temporal lobe, which processes sounds and stores memories, a patient might experience hearing or memory loss.
A brain tumour diagnosis can trigger fear and uncertainty. McCall’s experience shows that tumours can be hidden and silent and might only be found by chance. But there is growing hope in existing and evolving treatment options for different tumour types.
The ultimate take-home message: always see your GP if you experience any of the above symptoms.
Dan Baumgardt does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
