A mother discovered she had breast cancer after being hit in the chest by a ball kicked by her teenage son.
Karen Cooper, 42, was hit as she played with son Zac, 15, while on holiday in Mallorca.
The next day, as she was putting on sun cream, she noticed the area was sore and so when she returned home to Manchester she went to see her GP.
She said: "When I went to the doctor, there was a little lump there - but I was told it wouldn't be anything serious."
But tests and a biopsy later revealed that she had aggressive stage three cancer, which can be life-threatening.
Karen said: "I just feel so lucky that Zac hit me in the chest with the ball, or I wouldn't have noticed the lump. I didn't feel ill and wasn't in any pain."
She said Zac had been worried he had caused the cancer. The mother-of-two said: "At first he thought that he had caused it, so we had to reassure him.
"He was shocked and upset but we told him that he had found it for me. He saved my life, definitely."
Karen had six rounds of chemotherapy at The Christie hospital in Manchester, and then underwent surgery to have the lump from her breast and the surrounding lymph nodes removed.
In April 2011, after 15 sessions of radiotherapy, she was told the cancer was no longer present. And this summer, she ran a Cancer Research Race for Life this summer.
Cancer Research UK says that physical injury of a breast is unlikely to result in cancer.
Instead, because the area is sore or injured, the breast itself is being examined and followed more closely than usual, and that is why breast cancer is detected, rather than it being due to the actual injury.