Experts reveal terrifying dangers of the ultra-rare brain tumor that has struck Davina McCall – from speech problems to sudden death

Davina McCall shocked fans today after revealing she is undergoing brain surgery to remove a tumor.

In an Instagram post, the TV presenter, 57, said she had a ‘very rare’ colloidal cyst, which is not cancer and only affects three in a million people.

The Masked Singer judge was only diagnosed by chance after signing up for a full body scan.

“I buried my head in the sand for a while. I saw a few neurosurgeons, had quite a few opinions and realized I had to get them out,” she says.

‘It’s quite big, 14mm wide and needs to come out because if it grows it would be bad. I’ll have it removed.’

The slow-growing tumor, usually found in the center of the brain, is not cancerous. But being benign doesn’t mean it’s harmless.

If they grow large enough, patients are at greater risk of memory problems or even comas. Left untreated, they can even be fatal.

Here, MailOnline reveals everything you need to know about the condition.

“I kind of buried my head in the sand for a while. I saw a few neurosurgeons, had quite a few opinions and realized I had to get them out,” she said in an Instagram post today

Colloid cysts, which are filled with a thick, gel-like substance called colloid, are often asymptomatic and are found incidentally during imaging tests.

If symptoms occur as the tumor grows, they are typically reported to include headaches that are most severe in the morning upon waking, nausea, and blurred vision.

Vertigo and double vision are other important symptoms.

According to American neurosurgeon Dr. Anthony D’Ambrosio, the growth develops in the third ventricle of the brain.

Ventricles are spaces filled with cerebrospinal fluid (CSF) – a clear, colorless fluid that surrounds and protects the brain and spinal cord.

If a colloidal cyst is large enough, it hinders the movement of cerebrospinal fluid in the brain.

This results in a build-up of cerebrospinal fluid in the ventricles of the brain, leading to the condition hydrocephalus, which causes a range of distressing symptoms including personality changes, visual disturbances and speech problems.

If the blockage becomes severe enough, it can lead to a coma.

Colloid cysts, which are filled with a thick, gel-like substance called colloid, are often asymptomatic. Pictured is a case report published in the journal Wiley, showing the cyst in the center of the brain scan (gray circle)

Colloid cysts, which are filled with a thick, gel-like substance called colloid, are often asymptomatic and are found incidentally during imaging tests. Pictured with partner Michael Douglas in September

Davina told her Instagram followers this morning: ‘I’m having it removed via a craniotomy through the top of my head here, and through the two halves of my brain, through the middle.’ Pictured with her partner Michael Douglas and daughter Holly Robertson in January

In other cases, it can even result in a brain herniation, where tissue moves within the skull and potentially blocks blood flow to the organ.

If the increased intracranial pressure is not treated, sudden death is possible.

Colloidal cysts are usually treated with surgery – a craniotomy. This requires removal of some of the bone from the skull to expose the brain.

Where the opening is made in the skull depends on a number of factors, including tumor size.

Davina told her Instagram followers this morning: ‘I’m having it removed via a craniotomy through the top of my head here, and through the two halves of my brain, through the middle.

“Take the cyst, drain it, take it out, Bob is your uncle.”

Instead of performing a craniotomy, a neurosurgeon can also treat the colloid cyst using a minimally invasive procedure called endoscopic craniotomy, in which a small incision is made just behind the hairline.

In both traditional craniotomy and endoscopic craniotomy, the colloidal filling is gently drained from the cyst and then the cyst wall is closed.

According to Dr. Ambrosio, most patients who undergo an endoscopic craniotomy can return home within a day or two. A craniotomy requires much longer recovery times.

Davina revealed she was feeling ‘up and down’ and explained she would be in hospital for at least nine days before coming home.