It’s often confused for a cyst, and one can only wonder the horror that befalls a new mother when she finds out that her newborn was born with a giant cyst in its belly. Imagine how terrified and shocked she must be when she finds out it’s “foetus in fetu,” or “fetus within a fetus,” an incredibly rare disorder.

Such is the sad case of an Indian child born in a Kengeri hospital in late 2011.

A group of surgeons operated on the two-month-old baby and removed what would have been his twin.

While in the womb, the unborn child had descended into his brother’s belly, where it developed and was mistaken for a “cystic mass.”

After the mass was removed, doctors examined it and, according to Dr. Keshav Murthy, assistant professor of pediatric surgery at Rajarajeshwari Medical College, it revealed “two limb-like structures at the upper end of the mass, and well-developed bone, cartilage, friable pale areas and cystic structures.”

Sadly, the mother, Sahana SP, 20, thought the issue was due to nothing more than a fibroid mass on her kidneys, which doctors told her would simply be removed after the birth of her son.

The child was born on December 30, 2011.