In a shocking discovery, doctors in the US have found an embryonic twin complete with bone, hair and teeth in the brain of a 26-year-old Indian woman undergoing surgery for a suspected tumour.
Yamini Karanam, a PHD student at Indiana University, sought medical help last September after she started having trouble reading and talking.
At one point Karanam, from Hyderabad, could barely eat and pain ran from her head throughout her body.
Karanam was diagnosed with pineal tumour after doctors spotted what they thought was a cyst on Karanam's pineal gland, a tiny pea-like structure in the centre of the brain, 'The Washington Post' reported.
In March this year, Karanam connected with Hrayr Shahinian, a doctor performing radical 'keyhole' brain surgeries at the Skullbase Institute in Los Angeles.
Shahinian made a tiny incision in the back of Karanam's head, then strung an endoscope into her skull and through a natural channel in her brain to the site of the suspected tumour.
However, Shahinian was shocked to discover that the tumour was actually a teratoma: a clump of bone, hair and teeth.
Some doctors believe teratomas are twins that never quite develop and are instead absorbed into the surviving baby's body.
Shahinian successfully removed the teratoma and now expects Karanam to make a full recovery.
Karanam told NBC 4 that she was stunned to learn that her tumour wasn't just a lump of cells, but her "evil twin sister who's been torturing me for the past 26 years.
