This woman was relieved when doctors discovered an embryonic twin in her brain, because that's better than a tumor.

Indiana Ph.D. student Yamini Karanam, 26, started to get concerned recently when she suddenly found it harder to focus while reading and couldn't understand what other people were saying.

She visited a neurologist, but didn't get a clear answer on what was wrong until Dr. Hrayr Shahinian of the Skullbase Institute in Los Angeles used a special keyhole surgery to look inside her brain and see the tumor.

Only it wasn't a tumor. It was her twin. Or what Karanam jokingly told NBC Los Angeles was her "evil twin sister who's been torturing me for the past 26 years."

What Dr. Shahinian found was an embryonic twin who had been in utero with Yamini but failed to develop. The twin even had teeth and hair—cool/gross! Shahinian says this is only the second one of these he's ever seen in a brain after doing almost 8,000 surgeries.

Sources: NBC Los Angeles