A baby boy born with two left arms is set to undergo surgery to remove one of them in Shanghai.
Jie-jie cries when his arms are touched
However, the team at the Shanghai Children's Medical Center are unsure how best to proceed, and have yet to set a date for the operation.
Neither arm is fully functional and tests have so far been unable to determine which was more developed.
The boy, Jie-jie, cries when either of his left arms is touched, but smiles and responds normally to other stimuli.
The arm closer to the body is very slim and is always bent.
The other one is normally shaped but does not move unless it is pulled, and does not have a palm.
Jie-jie, who is in stable condition in the intensive care unit, was born on 1 April at a small hospital in Anhui Province.
He is also reported to have just one kidney, and may have problems that could lead to curvature of the spine.
Dr Chen Bochang, head of the orthopaedics department at Shanghai Children's Medical Center, said: "His case is quite peculiar.
"We have no record of any child with such a complete third arm.
"It's quite difficult to decide how to do the operation on him."
Dr Chen's hospital is one of China's most experienced in dealing with unusual birth defects, including separating conjoined twins.