A woman who believed she couldn't shed weight on Mounjaro because she was "lazy" learned she had a 12kg cancerous tumour developing inside her. Becki Ward, 33, chose to begin weight loss injections after finding it difficult to drop the pounds naturally, but was baffled as they didn't appear to be effective.

Following stomach pains and night sweats, she visited the doctors and, after five months of tests, was eventually diagnosed with pseudomyxoma peritonei - an exceptionally rare form of mucinous cancer. Becki's stomach continued to expand so dramatically it appeared she was "having twins", and in August 2025, she underwent surgery to remove the 12kg tumour, as well as removing some of her organs and having a full hysterectomy, placing her into early menopause.

Becki, a trainee education mental health practitioner from Great Yarmouth, Norfolk, said: "I've always struggled with my weight, so I decided to start taking Mounjaro in October 2024. At first it was working well and suppressing my appetite, but then I realised I wasn't losing weight as fast as everybody else.

"I assumed it wasn't working because I'm in my 30s, I was lazy, or I was overeating. I've always struggled, so I thought it must just be me.

"Then I started to get night sweats and stomach pains, I'd read on the news about people getting pancreatitis from Mounjaro and I started panicking and thought that's what I had. After five months of testing, I was diagnosed with pseudomyxoma peritonei.

"I was so shocked when I got the diagnosis, the thing I've always been most terrified of is getting cancer. I just wasn't expecting it, and I immediately thought the worst.

"My stomach continued to grow, and days before the surgery, I looked like I was about to give birth to twins. By the time they removed the tumour, it was huge, it weighed 12kg.

"I also had a hysterectomy and was plunged into early menopause. Doctors gave me HRT, which helped a lot, but it's really hard to find any support or any information for women going through menopause at my age."

Becki has constantly battled with her weight and in October 2024 chose to begin taking 7.5mg Mounjaro after tipping the scales at 18st 7lbs. Initially, the injections proved effective and she shed pounds, but she grew puzzled when she had merely lost a stone across three months.

"Some people were losing half a stone a week, and I was only losing one or two pounds in the same amount of time," she explained. She began experiencing night sweats, though attributed this to a Mounjaro side effect initially.

However, when abdominal pains struck, she visited her GP for blood tests and organ checks and was stunned when tumour markers showed up. Medical professionals first suspected Becki had ovarian cancer, though they conducted further tests to confirm.

They found a 22cm cyst on Becki's left ovary, but doctors required five months to eventually diagnose her with pseudomyxoma peritonei - a cancer so uncommon that just two hospitals in the UK can provide treatment. Pseudomyxoma peritonei is an extremely rare form of mucinous cancer that is distinguished by the accumulation of a jelly-like material called mucin in the abdominal cavity.

It's dubbed "jelly belly", as it triggers swelling in the stomach, which explains why Becki couldn't shed weight. Symptoms frequently remain absent until a substantial quantity of mucin has accumulated, prompting doctors to suspect that Becki may have harboured the cancer for five years, unknowingly.

Becki was scheduled for an eight-hour operation in August 2025, which ultimately lasted 11 hours, as the cancer had progressed further than doctors originally anticipated. Doctors eliminated all of the visible evidence of cancer by removing Becki's spleen, her appendix, her gall bladder, her omentum (a fold of fatty tissue in the abdomen), her peritoneum (a protective layer inside the abdomen), performed a total hysterectomy and extracted a 12kg tumour.

Subsequently, directly after the operation, they administered heated chemotherapy throughout her abdominal cavity to eliminate microscopic cancer cells invisible during surgery. The procedure triggered premature menopause in Becki at merely 33, signifying she will never have the ability to bear children.

Fortunately, Becki and her husband Ed, 36, had already reached the decision against starting a family prior to the diagnosis, though she acknowledged she couldn't fathom the emotional impact if she'd harboured such aspirations.

"I can imagine it would be devastating for a lot of people as 33 is the age when so many people want to have a baby," she said. Following five days in intensive care and a combined fortnight in hospital, Becki was discharged and commenced HRT to manage her menopausal symptoms, including hot flushes.

Becki is now gradually recuperating, but whilst grappling with fatigue and limitations lifting heavy items, she is largely coping well. Medical professionals now consider Becki to be cancer-free, however she must attend routine medical examinations for the subsequent two decades, as the disease carries a 30% probability of returning.