A self-confessed "it girl" is having her entire shoulder removed and replaced with metal after doctors discovered an avocado-sized tumour in her left shoulder joint.

Cat Holden, 23, went from working in London and going on holidays abroad, to living back with her parents and needing 24-hour care and says the diagnosis ruined her life.

She experienced her first symptoms - a shoulder twinge and weak arms - a year before diagnosis, initially believing she'd injured herself at the gym.

But after a round of physiotherapy and a misdiagnosis of tendonitis, Cat visited a private health clinic asking for an MRI.

On January 10, 2024, doctors spotted an avocado-sized tumour in her left shoulder and, on March 8, she was told it was cancerous.

She's entering her fifth round of chemotherapy of 18 and looking at having her shoulder and humerus bone removed, but Cat says the ordeal has taught her to "appreciate life much more".

Cat, an assistant underwriter, from Ingatestone, Essex, said: “Getting cancer was a really pivotal point in my life because everything was happy-go-lucky and I was confronted by something I never thought would happen.

“It’s devastating hearing, at 23, you’ll never have full function of your shoulder again.

“Being referred to Macmillan and told I’d need six to nine months of chemotherapy - it was the darkest day of my life.

“I still can’t get my head around it.”

Cat was on a family adventure holiday in Great Yarmouth in March 2023 - when her left shoulder began twinging while rock climbing.

She said the pain continued after she came off the wall, but she wasn’t worried enough to go to the GP, thinking she’d slightly injured her muscle.

But in August, she felt her shoulder twinge again while swimming at Bracklesham Bay, West Sussex - and she was “hardly able to keep her head above water”.

When she got home, she booked an appointment to see what was going on.

“The doctor said it looked really inflamed,” she said.

“But they couldn’t see anything else on the ultrasound, so I was diagnosed with tendonitis.

“I was told it was an easy fix - I just needed rest and ibuprofen.

“I guess I always thought it was something more - maybe a tear in the tendon.

“I did some physio exercises on an app too - once a week for six weeks.”

Cat travelled to Sydney, Australia, after finishing the physiotherapy, for the “trip of a lifetime”.

Bit while climbing the Sydney Bridge and skydiving - she began to notice “something was really wrong”.

Her shoulder went from aching to disrupting her sleep and it would throb.

She said: “There was something very apparent to me that something was really wrong.

“I got home from Australia in mid-November - I had no lumps, no bumps.

“But I couldn’t lift my left shoulder above a right-angle.

“I’d lay awake every night and feel a pulse in my shoulder.

“Even my physiotherapist noticed I’d really lost strength in my arm.”