The parasitic twin can develop an entire organ system with a torso and limbs inside the host twin but lacks critical functioning of many vital organs and is essentially considered a tumor.

The girl’s parasitic twin had a head, heart, arms and legs but no nervous system. It had invaded many of her main blood vessels, bladder, uterus and ovaries.

The condition had caused the infant’s belly to swell while her general health had been declining, according to a recent report by local newswires.

The girl is now recovering after surgery, which took place on Sunday, said Liem.

Had the infant’s operation been delayed, her life may have been endangered as the fetus had invaded critical blood vessels and the entire abdominal region, he said.

Fetus in fetu is a rare abnormality occurring in 1 out of every 500,000 live births.

Reported by Thanh Nien Staff