I thought my bloating was IBS…but it was actually a giant tumour the size of a newborn baby

A super-fit Birmingham woman who fainted shortly after completing a triathlon was shocked to discover that a deadly tumour had been growing in her abdomen for months. The tumour had now grown to a whopping 11lbs, larger than the average newborn.

Samantha Boswell, 53, had been experiencing mild back pain and bloating before her sudden collapse, but she blamed the symptoms on her extreme exercise routine and irritable bowel syndrome.

However, she did not seek help and the disease peaked minutes after she completed the astonishing physical challenge in August 2022.

She was rushed to the hospital, where doctors discovered a massive soft-tissue tumor in her abdomen, near her kidneys. In medical terms, this tumor is known as a retroperitoneal sarcoma.

After life-saving surgeries, including the removal of part of her intestine, it took more than a year for the mother of one to walk properly again.

“At first I was numb and couldn’t believe it,” she said, recalling the day she was diagnosed.

‘I feared for my life and honestly thought my sporting career would be over if I survived this.

‘And then it immediately occurred to me: how do I tell my son? [I was scared] about the fact that I wasn’t there for him and couldn’t see him grow up.

‘I felt like I was letting him and my husband down.

I found [the size of the tumour] hard to fathom, but my surgeon was very positive from the beginning that he could save me. I went from trying to be positive all the time to just being terrified.’

During a gruelling Ironman UK challenge, the 53-year-old sports massage therapist felt a sharp and sudden pain in her abdomen that quickly became ‘unbearable’ – and she collapsed after crossing the finish line

After the event, she noticed a bulge in her abdomen, which after several scans was confirmed as retroperitoneal sarcoma – a cancerous tumor weighing as much as 5 kilos – larger than the average newborn.

Emergency surgery was performed to completely remove the tumor.

Because of her size, she also had to lose a kidney, an adrenal gland, part of her intestines and part of her abdominal wall, as well as part of her aorta and psoas muscle.

According to Sarcoma UK, retroperitoneal sarcomas often cause an enlargement of the abdomen. Recognizable symptoms include a lump in the abdomen, a dull ache in the abdomen or back, and severe pain with bleeding.

Data show that approximately 15 percent of all soft tissue sarcomas are located in the retroperitoneum.

In the UK, around 3,000 patients are diagnosed with soft tissue sarcomas each year. In the US, the figure is probably three times higher.

Surgery is usually the main treatment for cancer, and surrounding organs may be removed.

Ms Boswell, who initially suffered from back pain and IBS symptoms, thought the bulge was simply due to her age and other symptoms resulting from her active lifestyle. However, following her aforementioned diagnosis in August 2022, emergency surgery was performed to completely remove the tumour

After her surgery, Mrs Boswell spent the next two months in hospital recovering, but she was determined not to give up and took small steps towards renewed training.

‘When I walked to the toilet and back in the hospital, I kept track of the time.

‘I kept track of the distance on my fitness watch and added a little bit every day.

“It was a triumph to walk a quarter mile through the hospital corridors.

‘It took a year before I could walk properly again, but after that nothing could stop me.

‘I [began with] ‘Sitting on a stationary bike for 20 minutes to get my legs moving and from there I gradually built up my fitness.’

After her surgery, Mrs Boswell spent the next two months in hospital recovering, but she was determined not to give up and took small steps towards renewed training.

Now she is training for her next race and has also written a book entitled: Ironman, Me and The Big C, to share her journey and inspire aspiring triathletes, and to give hope to anyone facing a similar diagnosis.

She started racing again this year and has since completed a triathlon for Sarcoma UK, a charity that helps people with the disease, taking first place in the women’s category.

She started racing again this year and has now completed a triathlon for Sarcoma UK, a charity that helps people with the disease, taking first place in the women’s category.

She is currently training for her next race and has written a book called Ironman, Me and The Big C. With this book she wants to share her journey and inspire aspiring triathletes and give hope to anyone who is dealing with a similar diagnosis.

Mrs Boswell added: ‘I really love what I do.

‘I love running, competitions and fresh air. It’s my medicine.

‘I’ve always wanted to improve myself and get the best out of myself.

‘I want to decide for myself when I stop competing, and not have cancer make that decision for me.’

‘I thought if I can’t run, I’ll swim and cycle instead.

‘I have to pinch myself when I look back at what I’ve been through.

‘I never thought I would ever race again.

‘Don’t make excuses for things that aren’t quite right with your health, and be grateful for the everyday things and the simple things in life.

‘I still have a long way to go before I can achieve my dreams and get back to where I was.

‘But I love racing again – even more than before I was diagnosed – and I see it as a real blessing.

‘My dream is that the sarcoma never comes back and that I can watch my son grow into a man, while sharing my life with my husband.’

Kerry Reeves-Kneip, communications and fundraising director at Sarcoma UK, said: “Sam’s achievement is truly awe-inspiring.

‘Imagine being shocked when you are diagnosed with 5kg of sarcoma, followed by major surgery where you lose a kidney.

“But Sam didn’t just recover — she thrived and pushed herself to compete in one of the most demanding sports in the world. Her resilience and determination are truly remarkable.”