Mass on girl’s back contained a breast, an arm with two fingers from undeveloped twin (Warning: Graphic Image))

A 11 years old girl had a life-changing surgery to remove a growth doctors have identified as part of an identical twin that had failed to develop and was enveloped by its sister.

The mass on her back using an X-ray revealed abnormal curvatures of the spine which contained a breast, an arm with two fingers and Professor Baogan Peng was quoted in the journalBMJ Case Reports, as saying: ‘Based on physical examination and imaging findings, a diagnosis of fetus in fetu was made preoperatively.’



Fetus in fetu in an incredibly rare condition that affects only one in five million live births. It is a condition where the malformed foetus is found in the body of its twin. The foetus is found in the abdomen in 80 per cent of cases, although there have been reports of it occurring in the skull. However, this is the first time that is has been reported in the back.

The girl also suffered from diastematomyelia, which is a congenital disorder in which the spinal cord is split.
Prof Peng, who is an expert in spinal surgery at the General Hospital of Armed Police Force in Beijing, said doctors successfully removed the parasitic twin, despite there being no clear way of separating them.

He added that a later analysis also found digestive tract lining in the tissue.