Washington: American doctors were shocked to find that an Indian computer science PhD student from Hyderabad who underwent brain surgery had an embryonic "evil twin" instead of a tumour in her head. The 26-year-old Yamini Karanam had jokingly called her "evil twin sister who's been torturing me for 26 years".

According to NBC, Karanam, who was studying at Indiana University, was unaware of what was happening in her head until she underwent a procedure designed to reach deep into the brain to extract the tumour.