Jon Caterer, 45, is a Duty Manager and Swift Water Rescue Trainer from Wales, a husband to Emma, and a father to their young son Freddie. What began as a subtle change to his sense of smell developed into a life-altering diagnosis of a brain tumour located deep within his brain, near the brain stem.
Since his diagnosis in 2021, Jon has undergone nine complex surgeries and faced repeated complications related to shunt failure and infection.
Jon tells his story…
I’d had a bad sense of smell for years. Being a typical bloke, I ignored it. Then I met my now wife Emma. As it got worse Emma insisted I get it seen to, I thought it could be COVID-19, she thought it was hay fever. I eventually went to my GP which led to an ENT referral and an MRI scan at University Hospital Wales in Cardiff. When the results came back, they said I had really bad sinusitis – and a brain tumour.
I still remember the phone call. It was surreal. I genuinely thought they had the wrong number. At that point, I still had my head firmly in the sand.
The tumour was located in my fourth ventricle, deep in the brain, close to where the spinal cord joins the brain. It’s a very sensitive area.
My first elective surgery was in October 2021 and lasted nine hours. Beforehand, they explained the risks of loss of sight, mobility, loss of movement in my left arm or the left side of my face, visual disturbances, balance problems and even death. It was frightening to hear. It didn’t fully sink in at the time, but surgery was the only option. This was during COVID-19. My then fiancée Emma wasn't even allowed to accompany me into the hospital; I had to go in alone.
When I came out of surgery, I was placed on a high-dependency neurological ward, which is never a good sign. My vision and balance were badly affected because of the location and intrusiveness of the surgery. It took me weeks to learn to walk again and I was sleeping for up to 18 hours a day.
They had opened the back of my head, removed part of my skull and separated the layers of tissue holding the fluid in my brain and navigated through the cerebellum to reach the fourth ventricle where the tumour was. Thankfully the surgery was successful in removing all of the tumour, and for that I am incredibly grateful.
To date, there has been no further growth of the tumour.
In January 2022, I developed complications. This is where the real journey began for me. I had a cerebrospinal fluid leak (CSF), the fluid that surrounds the brain was leaking from the back of my skull. I was told it might settle on its own. Then Emma noticed clear fluid leaking from the top of my scar. She took a photo, and I emailed it to the neurosurgical team, who responded immediately and told us to come in that day for emergency surgery.
To address the CSF leak they reopened the wound on the back of my head, applied some surgical glue to assist with healing and cleaned it up. A few days later, I coughed and suddenly felt my shoulder was wet. The pressure caused the fluid to burst through the wound again, I was experiencing hydrocephalus. The natural pathway for cerebral fluid had become blocked during surgery number one and the fluid was building up inside my skull until it found its only way out through the surgical wound. This led to my third surgery, and the fitting of the first VP shunt.
Around this time, pathology results confirmed I had a grade 1, non-cancerous, unclassified brain tumour.
Eighteen months passed, and everything was looking positive; we were adjusting to our ‘new normal’. I married Emma, and we were expecting our first baby in just a few months. We were living the life we had planned. Then the next setback happened, I started experiencing double vision again, headaches and my balance just wasn't improving even with rehabilitation physiotherapy, it felt like I was going backwards. The VP shunt had blocked, and the CS fluid had nowhere to go. A life-threatening situation, back into surgery and the first shunt revision was completed.
It was terrifying. There were huge risks, and no one could guarantee things wouldn’t go wrong.
Unfortunately, just days later, the new shunt also blocked, and I was back under the knife and having the shunt replaced again, surgery number five. This time with a new entry point through my brain to minimise risk of blockages. By July 2023, I was mentally and emotionally exhausted, but we slowly got back to our new normal again. Many of the symptoms that came with the hydrocephalus had subsided but not completely disappeared.
In April 2025, I suddenly developed severe double vision again. Despite multiple A&E visits and scans, I was repeatedly told the shunt was working fine. I was sent from A&E to my GP, to the Ear Nose and Throat clinic, to eye casualty, and back again. I felt like I was going around in circles. I even sought a private second opinion, I was desperate for an answer, things don’t change dramatically overnight without reason.
With the help of a private consultant, in June 2025, I underwent surgery number six for intercranial pressure monitoring. This showed quite quickly that the pressure in my head was dropping dangerously low when I was standing, far below normal levels. This confirmed the shunt was siphoning fluid from around my brain. Surgery number seven followed the next day to replace the valve with a programmable one with anti-siphon protection.
Shortly after In August 2025, my wife noticed clear fluid coming from a previous surgical scar on my head. This time the shunt was infected and I was admitted for emergency surgery number eight where the whole shunt system was removed. I spent a week in hospital hooked up to an external drainage system while the infection was dealt with.
Thankfully, the infection hadn’t spread deeply into my brain. A week later, I had surgery number nine to fit a new shunt on the opposite side of my head.
I'm now under routine monitoring. It has been a long, exhausting journey and I'm still not at the finish line. I live in fear that a malfunction may happen again at anytime.
If everything had gone smoothly, I wouldn't have needed the last four brain surgeries. Care for brain tumour patients in Wales needs to improve; there needs to be better communication, better follow-up, and more joined-up thinking. I cannot fault the individual care of each staff member who has been a part of my journey, it's the process that has let me down.
That's why I'm supporting the Manifesto for Wales, which has just been launched. It was a monumental moment to be at the Senedd when it was presented to the parliamentarians who have the power to make things better for patients like me in the future.
I am grateful for the initial surgery; there has been no recurrence with my tumour. My message to others is simple: listen to your body. Sometimes scans don't show everything, and you have to keep pushing to be heard.
A diagnosis of a brain tumour is life-changing in ways that are hard to put into words. My instinct at first was to keep it private and try to process everything on my own which, in hindsight, is an enormous burden for anyone to carry.
My wife told me about a documentary called The River Runner, a documentary about a world-class kayaker navigating life after being diagnosed with a brain tumour. With some anxiety, I watched and as a kayaker myself, I found his story deeply relatable. Seeing someone articulate emotions I hadn't yet been able to express gave me permission to open up about my own diagnosis. That moment marked a turning point and helped me begin to process and come to terms with what was happening. I'm yet to get back on the water; my balance and double vision are a daily battle, but I'd like to teach our now two-year-old son one day to paddle and make memories of his own adventures.
Since then, I've been overwhelmed by the kindness and support of the people around me. That support has been absolutely vital not just for me, but for my family too as we've navigated the psychological impact of the past few years. It has been an emotional roller coaster and knowing we were not facing it alone has made all the difference.
Jon Caterer
March 2026
One in three people in the UK knows someone affected by a brain tumour. This disease is indiscriminate; it can affect anyone at any age. What’s more, brain tumours continue to kill more children and adults under the age of 40 than any other cancer yet, to date, just 1% of the national spend on cancer research has been allocated to this devastating disease since records began in 2002.
Brain Tumour Research is determined to change this.
If you have been inspired by Jon’s story, you may like to make a donation via www.braintumourresearch.org/donate or leave a gift in your will via www.braintumourresearch.org/legacy
Together we will find a cure.
