A woman had nine organs removed during a 10-hour operation after being diagnosed with a rare cancer that began in her appendix.
Claire Gerring, 42, a hairdresser from Wantage, Oxfordshire, was initially referred to John Radcliffe Hospital in November 2022 with suspected endometriosis and was placed on a waiting list for an investigative laparoscopy in May 2023. However, after experiencing intense pain on her right side, a positive Faecal Immunochemical Test (FIT) led to a colonoscopy.
Doctors discovered her appendix was inverted, and a CT scan revealed malignant tissue on the organ. A biopsy on May 6, 2025, confirmed she had stage four Pseudomyxoma Peritonei (PMP), a rare cancer that typically originates from a tumour in the appendix. She was referred to Basingstoke and North Hampshire Hospital, one of only two hospitals that specialise in PMP. The cancer in her appendix had ruptured, meaning there were other nodules in the rest of her body.
The mother of all surgeries
On July 15, 2025, Claire, who is mother to sons Oscar, 15, and Spencer, 14, underwent a 10-hour operation to remove nine organs: her appendix, ovaries, fallopian tubes, gall bladder, spleen, uterus and cervix. She also had her greater omentum, belly button, peritoneum lining and part of her bowel removed. Her liver was partially cut away, and her diaphragm was scraped and bladder stripped.
During the surgery, Claire had HIPEC chemotherapy, where heated chemotherapy is circulated around the abdomen. After four-and-a-half weeks in hospital, she was discharged. She has been left with bowel problems but currently has no evidence of disease and will be monitored for the next 20 years.
Claire said: "I felt really quite scared and quite alone after my diagnosis. When you’ve got a rare cancer and it’s not something you’ve heard of before, there are not a lot of people to talk to about it."
She added: "I was told by surgeons before my operation what they would remove. On top of that they cut part of my liver away and scraped my diaphragm and stripped my bladder. It’s a lot to process. It’s quite scary, but I’m lucky I had professionals who knew what they were doing. It’s called the mother of all surgeries because of the severity of it."
Discovery of the cancer
After struggling with pain in her side and asking for her laparoscopy surgery to be expedited by her GP, a positive FIT test and colonoscopy in March 2025 revealed Claire’s inverted appendix, which needed a CT scan. Her original endometriosis surgery was set to go ahead on April 11, 2025.
Claire told Talk to the Press: "But on April 10, I phoned up just to double check they’d got my CT scan results back as the next day I was now having investigative surgery. That’s where I was told I had malignant tissues in my appendix. At that point I wasn’t too worried because I thought, ‘well I don’t need my appendix’. Thirty seconds later, my gynaecology lady rang and said ‘Claire this is serious’ and that my surgery wouldn’t be happening tomorrow."
Investigative surgery on May 6 revealed the cancer was not contained to her appendix. "When the tumour ruptures it releases mucin, which is a jelly-like substance," Claire said. "It’s often called ‘jelly belly’. Your abdomen fills up and coats all your organs with mucin."
As a result, Claire needed cytoreductive surgery with HIPEC to remove all her affected organs.
Recovery and fundraising
"I’m coming up to my year's anniversary and I’m still left with complications in my bowel and I’ve been back in hospital in between," she said. "With a lot of cancer you’re told you lose weight, but with this one I put on weight and looked four months pregnant. I thought I’d just got to 40 and it was my middle-aged spread. But it was actually inside my abdomen."
She added: "Recovery is a slow process, obviously, like most surgeries, if you have your appendix out the recovery time is six to eight weeks. Times that by 11 (and) it’s a long time. I had a bowel obstruction and was back in hospital for a 10-day stay recently. I’m still grateful, it’s a small price to pay. Basically what they say is you’re never back to your old self, you just get used to the new you."
Now a year into her recovery, Claire has thrown herself into fundraising for charity Pseudomyxoma Survivor, throwing a masked ball on July 11, 2026. She has raised £16,002 so far for the charity through Just Giving and other events.
On the night, she said: "I just feel my main purpose for doing this is raising awareness about the rare cancer and Pseudomyxoma Survivor. I believe deeply that if you’re willing to take, you must also be willing to give back. And here I am today, standing in front of you, living that promise."
She added: "I feel so passionate about giving back to this charity which stepped in and helped me at the point in life when it felt uncertain and alone. They also support research and have recently given £100,000 towards — would you believe it — the research project is called The Beacon Project. They are creating a blood test to detect the cancer and recurrence way before CTs can even pick it up. Tonight, we are part of supporting these amazing breakthroughs."
Maddy Lomas, trustee at Pseudomyxoma Survivor, said: "As a charity, we are incredibly touched by the effort and generosity behind this fundraising event. What makes it even more special is that it has been organised by someone who knows first-hand what it means to face a diagnosis of PMP."
She added: "Having received support from Pseudomyxoma Survivor during her own journey, Claire has now turned that experience into an opportunity to give back and support others who are walking a similar path. This is truly commendable and a wonderful example of how personal experiences can be transformed into something that brings hope and support to others."
"For a small charity, the £16,002 raised is incredibly significant and will have a lasting impact. It will help us continue our mission of providing support to people affected by PMP, raising awareness of this rare disease, and contributing towards vital research that can make a difference for the future."
"However, just as important is the much-needed awareness Claire has created by organising and delivering this event. For a rare disease like PMP, every person who learns about the condition helps to increase understanding and could make a life-changing difference by helping someone recognise the signs, seek support, or feel less alone following their own diagnosis."
