When Yamini Karanam began having difficulty comprehending things she read or heard, the 26-year-old visited a doctor to get checked out.
Diagnosed with a brain tumor, the Indiana University PhD student underwent a minimally-invasive surgery to remove it, only for doctors to discover that the tumor was actually her embryonic twin! A rarity - but not unheard of - in modern medicine.
Scan shows where Karanam's embryonic twin was located. (Photo Credit: NBC Los Angeles)
The twin had never developed, and likely died in the womb in the early stages of her mother's pregnancy, when the embryos had not fully separated.
According to Dr. Hrayr Shahinian, it did have "bone, hair and teeth", likely because the mass begins as a normal fetus but becomes enveloped inside its twin - something known as "Fetus in fetu."
Karanam joked that the abnormality was her "evil twin sister who has been torturing me for the last 26 years."She is expected to make a full recovery.
Another instance of this came in 2009, when a man from England discovered he had a parasitic twin embryo living in his stomach, which then had to be removed.
Watch Karanam's interview with 'NBC Los Angeles' below:
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