Natalie Morton died in hospital following a cervical cancer jab at school
A girl who died hours after receiving a cervical cancer vaccination had an undiagnosed tumour in her heart.
Natalie Morton, 14, was given the injection at the Blue Coat Church of England School in Coventry.
An inquest at Coventry heard that her condition was so rare a pathologist had never seen it in a child before.
Deputy coroner for Coventry Louise Hunt found that Natalie's death was not linked to the HPV vaccine and recorded a verdict of natural causes.
Dizziness and headaches
She said: "Natalie had a previously unrecognised, extensive tumour of the heart which ultimately caused her death. It was a death that could have happened at any time."
Pathologist Alexander Kolar told the inquest the 15cm (5.9in) tumour was a malignant lymphoma, which was aggressive and growing rapidly.
"She was very vulnerable at any time, at sleep or any other point," he said.
The inquest heard Natalie had seen both a GP and a paediatrician in the months leading up to her death because she was suffering dizziness and headaches.
Her father, John Morton, said Natalie was assessed by a consultant five days before her death.
He added that his daughter had been unwell since late June last year.
Natalie's mother, Elaine Bullock, told the hearing that her daughter had suffered from infections in the period leading up to her death.
She said: "At that moment in time nobody knew that she had a tumour.
"We all did our best for Natalie and nobody knew what she had."
Natalie, from Stoke, collapsed less than two hours after being given the Cervarix vaccine on 28 September last year.
Her death sparked concern among pupils and parents, and led to a precautionary recall of one batch of the HPV1 Cervarix vaccine.