A devastated family have told of the extreme shock of learning their ‘sporty’ 15 year-old has inoperable, aggressive brain cancer – with the only warning sign striking hours before his diagnosis.

Callum Stone, 15, from Chelmsford, Essex, was hit by a debilitating migraine one January morning during the school day.

When mother, Sarah, 41, and step-father, Mark, 42, came to collect him, they realised that he was struggling to speak.

They took him straight to A&E and, terrifyingly, the teenager suffered three major seizures in the car on the way to the hospital.

Once the family arrived at Broomfield Hospital in Chelmsford, doctors admitted Callum for a week in order to carry out a series of test including CT and MRI scans.

Results showed some inflammation in his brain, which doctos put down to a viral infection.

Callum was later discharged with anti-seizure medication, as the medic in charge said she believed his health was ‘back to normal’.

However, the teenager was referred to Great Ormond Street Hospital in London for further monitoring, where doctors carried out a more detailed MRI scan.

 Devastatingly, the images revealed a ‘large tumour’ in Callum’s brain.

He underwent a biopsy on the mass on February 5 and on February 11, the family were informed he had a diffuse grade four glioma – a type of aggressive cancerous tumour that starts in the brain.

Grade four gliomas are the fasted-growing type and only around five to 10 per cent of sufferers survive longer than five years after their diagnosis.

Speaking of the diagnosis, Sarah said: ‘It was shattering.

‘In a matter of hours, our world has just completely been thrown upside down but a few months ago, we were just a normal family.’

Worse still, the family were informed that the tumour was inoperable, and growing like a ‘cobweb’.

‘Doctors would need to take away too much of the healthy cells,’ Sarah explained. ‘It’s quite hard to explain something like that to a child and his brother.’