Three-month-old Sam Esquibel, born with a foot in the brain, has been described as a 'miracle baby' after he survived the surgery to remove what was believed to be a tumour.
The surgeons have removed the growth from Sam's head, and the baby is now said to be fit and healthy.
Mum Tiffnie Esquibel has described his survival as a "miracle".
"He is a miracle. I just love him so much," the Telegraph quoted Tiffnie as saying.
The ultrasound tests on the pregnant mum showed that the unborn child had a tumour in his brain, which actually turned out to be a tiny foot during the surgery.
The brain also had other partially formed body parts including a second foot, a hand and a thigh.
The doctors believe that the condition was probably a teratoma, a type of tumour that contains hair, teeth, bones and body organs but usually does not occur in the brain.
Another theory is that Sam suffered from a condition called fetus in fetu in which one twin envelops the other, but the disorder is so rare that there have been fewer than 100 reported incidents in the world.
"When I went into hospital I thought, 'OK we're going to come out of here with a baby in our arms',"
"But we didn't - he was in another hospital. They told us it was a 50-50 chance whether he could make it through it or not," she added.