And Finally...

Doctors in the Indian capital, Delhi, have performed a life-changing surgery on a 17-year-old boy to remove his "parasitic" twin that was attached to his abdomen.

A parasitic twin is an underdeveloped conjoined twin that relies entirely on the host twin for survival.

They are extremely rare, with less than one case occurring, external per 100,000 births.

The teenager who had a fully developed extra set of limbs and a pelvis - sustained by a chest artery - underwent a two-hour surgery at Aiims hospital in Delhi.

Dr Asuri Krishna, who led the team of specialists, said the surgery was particularly challenging because of the patient's age.

"Only 40-50 cases of parasitic twins have been documented in world medical literature and, in those cases, the surgery had been attempted on children," Dr Krishna told the BBC.

With insufficient medical literature to guide them, the team had to rely on their "intuition, skill and knowledge", he added.

Parasitic twins form when one foetus partially develops while attached to the other.

In this case, the teenager had two fully formed legs, buttocks and external genitalia - weighing nearly 15kg - protruding from his abdomen.

Remarkably, the parasitic limbs could feel pain, touch and change in temperature.

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The teen was discharged four days after being admitted. He is healthy and has suffered no complications from the surgery, Dr Krishna says.