Image copyright Kevin O'Neill Image caption Kevin O'Neill has been living with severe chronic pain for 11 years

Kevin O'Neill is believed to be one of only 15 people in the world to have been diagnosed with the rare form of cancer called malignant myopericytoma - and now he is trying to track down the others.

The 48-year-old, from Inverkeithing in Fife, has been living with severe chronic pain for 11 years and has had five major operations in the past five years to remove tumours.

Two years ago he noticed the scar from a previous operation getting hot and then a swelling started on the wall of his chest on the right hand side.

Within weeks the swelling grew out of his shoulder blade to the size and weight of bowling ball.

Image copyright Kevin O'Neill Image caption The tumour on Kevin's shoulder blade was the size of a bowling ball

Kevin told BBC Scotland's Kaye Adams programme: "Myself and my wife have a good laugh about it now, the size that it was, but it was agony carrying it."

He says his previous tumours had been benign, but this one was cancer.

"If I had refused the surgery it would have killed me," Kevin says.

He underwent an operation to remove the massive tumour at the Royal Infirmary in Edinburgh, a 12-hour process which required him to be put into an induced coma for two-and-a-half days.

The surgery took place in October 2015 and required the removal of his ribs on the right side and part of his shoulder.

Surgeons said the tumour they removed was a size they had never seen before or since.

It was the weight of a newborn baby and the circumference of a dinner plate.

Image copyright Kevin O'Neill Image caption Kevin says it was "agony" carrying the tumour around

Samples from the tumour had been analysed in Edinburgh, then sent to the specialist Beatson West of Scotland Cancer Centre and research centres in the England.

The samples were finally sent to the United States before a diagnosis was reached of malignant myopericytoma.

A month after the surgery he got a call from his oncologist at Edinburgh's Western General.

Kevin says the oncologist told him there were just 15 people worldwide who had been diagnosed with this kind of cancer.

Recovery period

Two years after the operation, Kevin says his recovery is still ongoing.

"Because during the operation itself they took out the majority of my right ribs and quite a lot off my right shoulder, my chest was rebuilt as well," he said.

"As you can imagine it's quite a long recovery period."

Kevin retired from his job as a union organiser on medical grounds and has been to cancer support groups, but says he always felt like "the guy in the corner with the cancer nobody could pronounce".

So he has set up a blog and a Facebook page with the intention of finding the other 14 people with his condition.

He wants to set up a forum so they can speak to each other.

"Because it is so rare, there is not anyone who is an expert who you can actually talk to," Kevin says.

Just before appearing on the Kaye Adams programme, he was "shocked" to get a message from a man in California who says he is one of the 15.

"The smile I had on my face was like the Joker in Batman," he says. "It is really good."

Image copyright Kevin O'Neill Image caption Kevin has had to retire from his job on medical grounds

Kevin, who has three sons, says his health is "up and down".

He had a scare a couple of months ago when a build up of fluids appeared to be another tumour.

"I have been told that if I get a recurrence of a tumour in that area the best they can do for me is keep me comfortable," Kevin says.

"But you really just get on with it. A strong positive attitude helps me on a daily basis."