Teenager Endured Her Parasitic Twin For 5 Years Before Mass Of Flesh And Bones Was Discovered

A teenager in India initially complained of occasional abdominal pain and a feeling of fullness despite not having eaten much.

When eventually brought to the doctors, they discovered in the 17-year-old’s abdomen an extraordinary mass of bone, teeth and “hairy cheesy material”. It was her twin growing inside her.

This was the result of an extremely rare condition known as “fetus in fetu,” which translates to “fetus within fetus." Such a phenomenon is typically defined as a condition in which a developmentally abnormal fetus is found inside the body of its otherwise healthy twin. It is estimated to occur in 1 in 500,000 people worldwide.

Some researchers posit that fetus in fetu is a kind of teratoma – a type of tumor composed of all three major cell types found in a human embryo in its early days.

Such conditions are typically diagnosed in infancy or childhood. What makes this case so bizarre is that it was diagnosed in a teenager. To add, the mass appears to be the largest one ever discovered in a case like this. A CT scan uncovered that the teen had a big mass in her abdomen that appeared to contain multiple bones "resembling the shape of vertebrae, ribs and long bones," the authors wrote.

The lump on her abdomen had been steadily expanding over the last five years, according to the report, published Aug. 12 in the journal BMJ Case Reports. When surgically removed, the mass was approximately two-thirds the size of a full-term baby: It measured 14 by 6 by 4 inches (36 by 16 by 10 centimeters) "and was composed of hairy cheesy material, multiple teeth and structures resembling limb buds," the authors wrote. It also contained skin, hair and fat tissue, doctors said.

Unfortunately, doctors could not remove all of the parasitic twin’s tissue as some of it was too strongly bound to blood vessels supplying the gastrointestinal tract. Doing so could impede blow flow to the teen’s intestines. This simply means that there is a possibility of the left behind tissue turning cancerous. The girl will need to go for annual check-ups to screen for any development.

On the bright side, it has been two years since the surgery and she is doing well, according to the report.

"I was much worried about my abdominal lump," the teen was quoted as saying in the report. "After operation I am feeling very well … and my parents are also very happy."