A team of 13 doctors was readying to remove the parasitic twin of a 3-year-old Peruvian boy from his stomach, according to news reports.
Dr. Carlos Astocondor of the medical team at Las Mercedes Hospital in the northern port of Chiclayo said the condition was called fetus-in-fetu and happened in about one out of every 500,000 live births, according to the Associated Press.
Although rare, these cases are not unheard of. In 2008, doctors removed a 2-inch embryo from the body of a 9-year-old girl in Greece. In 2006, doctors found a half-formed twin with limbs, genitalia, hair — even fingernails – in the swollen stomach of a 36-year-old Indian man.
In the Greek girl's case, Medical News Today reported, the girl was suffering from stomach pains and diagnosed with a tumor growing on the right side of her belly.
"They could see on the right side that her belly was swollen, but they couldn't suspect that this tumor would hide an embryo," the website quoted Larissa General Hospital's director, Lakovos Brouskelis, as saying.
After surgery to remove the twin, the girl reportedly made a full recovery.
Surgeons in Peru, meantime, said the partially formed fetus in the boys stomach weighed a pound and measured nine inches.
It had eyes, bones and hair, but did not develop a brain, lungs, heart or intestines.