'Evil twin's' bones, hair, teeth found in woman's brain

What doctors initially diagnosed as a tumour in Yamini Karanam's brain turned out to be something more alarming.

The 26-year-old PhD student in Indiana started to struggle with understanding the world around her as her brain tumour grew.

In a video interview with NBC, Ms Karanam said: "(I had) problems with listening comprehension. If a couple of people are talking in the room I wouldn't understand what's happening."

Neurologists and neurosurgeons in Indiana could not agree on her treatment options, so the young woman started to do her own research.

She contacted doctors at Los Angeles-based Skull Base Institute, which came up with an unusual method of removing brain tumours using minimally-invasive surgery.

Conventional methods of removing brain tumours such as craniotomy involve cutting open part of the skull to expose and access the brain. This traditional type of brain surgery carries a high risk as the brain is a delicate organ and susceptible to damage, Dr. Hrayr Shahinian from the institute explained.

With the aid of digital imagery, Dr. Shahinian made a small incision on the back of Yamini's head and used an endoscope to "chisel away at the tumour."

During the surgery, he found a tumour made up of bone, hair and teeth. Doctors later identified the growth as a teratoma, a type of tumour that can contain three major cell types found in an early stage human embryo, according to medical texts.

The discovery led Dr. Shahinian and Ms Karanam to describe the tumour as an 'evil twin' who lurked in the depths of her brain for the past 26 years.

However, medical experts have dispelled the myth that the tumour is Ms Karanam's 'embryonic twin', Discovery News reported.

They said that a teratoma is made up of germ cells which can develop into any cell in the body. It is thus unlikely that the mass of bone, hair and teeth found in Yamini's brain came from a twin embryo.

A biopsy of the tumour confirmed that it was benign and the young woman is expected to make a full recovery in three weeks.