A teenager who had suffered with agonising periods for five years was shocked when doctors had to remove a 15cm cyst.
Rebecca Woodthorpe, 18, had to have her ovary removed because she said the mass twisted around and 'killed' the organ.
The A-level student had experienced sharp 'stabbing' pains in her stomach and legs every month since the age of 12.
Miss Woodthorpe claims doctors reassured her the pains were 'probably nothing' until her persistence led to an ultrasound.
Doctors eventually discovered a benign 11cm mass - which was 15cm by the time it was removed.
Rebecca Woodthorpe, 18, pictured with her parents, Anne and Paul, both 42, had suffered with agonising periods for five years was shocked when doctors discover a football-sized cyst
With an ultrasound, doctors eventually discovered a benign 11cm mass - which was 15cm by the time it was removed
Miss Woodthorpe had the cyst and an ovary removed in February 2018 because the cyst had twisted round the ovary, turned it black and 'killed it'
Miss Woodthorpe, from Lincoln, said at 12-years-old doctors said she had 'period pain' and put her on the pill.
She said: 'I was experiencing kidney pain in my left side, strong left thigh pain, abdominal and period pain and at each time of the month I would get a sharp stabbing that would last seconds but was horrific.'
Aged 14, in 2015, she went back to the doctors because the pain was getting much worse, but claims she was told it was 'probably nothing'.
The pain stepped up again, and she had an ultrasound on her kidney in November 2017, which revealed the cyst.
It is not clear how long the cyst had been there.
Most ovarian cysts are harmless and go away on their own but it may need to be removed if it is causing pain or could be cancerous.
Miss Woodthorpe said: 'At the scan I went in alone and the radiologist just happened to scan over my ovary before looking at the kidney and saw the cyst.
'The lady told me it would need further action and I really panicked as hospitals make me nervous.
'I left the room and told my parents. They were both shocked.'
The cyst was originally 11cm, but by the time Miss Woodthorpe was operated on - three months later - it was 15cm.
She had a unilateral salpingo-ophorectomy - when only one ovary and fallopian tube are removed - in February 2018.
The student had experienced sharp 'stabbing' pains in her stomach and legs that would last a few seconds every month during her period
Miss Woodthorpe had the cyst and an ovary removed and had to leave her A-level studies while recovering for several months. Pictured, in hospital
Miss Woodthorpe was in surgery for two-and-a-half-hours and in recovery for one hour. But she remained in
