After Lewis Deakin, an 11-year-old boy in the United Kingdom, had several benign tumors grow in the arteries of his chest thanks to a condition called arteriovenous malformation, he became the first child in the country to undergo a mastectomy—and he's taking it all in stride.

"He tells all the girls at school, 'I've been bitten by a shark,'" his mother tells the Telegraph. The malformations are rare, according to the Mayo Clinic, but they can occur anywhere in the body and disrupt the vital process of allowing arteries to pump oxygen-rich blood from the heart to the rest of the body, and veins to carry oxygen-depleted blood back to the heart and lungs.

It most often occurs in the brain and spine. Lewis first baffled doctors three years ago, when tumors began to grow in his chest, reports the Manchester Evening News.

His parents have since left the house as early as 5am to make the 160-mile round trip to Birmingham Children's Hospital dozens of times as the boy had 15 surgeries in just two years.

"It turned my life upside down," says his mother, who just had a baby. "I would just crumble if it was me but Lewis is really good." Her son made a speedy recovery after spending five days in the hospital following his April 2014 mastectomy, moving his arm normally within a month.

Another growth in his chest is going to be looked at later this month. (Double mastectomies are on the rise among men.)

This article originally appeared on Newser: Tumors Require Boy, 11, to Undergo Mastectomy

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