A Teen's Stomach Pain Was Caused by Remnants of Her Parasitic Twin

A 17-year-old-girl in Patna, India recently went to the hospital complaining of stomach pains and a large mass growing in her abdominal area. 

Doctor's were surprised to find that the cause of the pain was not a normal tumor. Instead, they found a mass that had teeth, hair, bones, fat, and cartilage.

The teen was suffering from a rare condition called fetus in fetu, in which the parasitic remnants of a twin are absorbed into a person's body in the uterus and remain there after birth.

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'Fetus in fetu'

After the girl arrived at the hospital complaining of having had stomach pain for years and the growing mass in her abdominal area, doctors took a scan.

"An abdominal contrast-enhanced computed tomography (CECT) scan showed a well-defined mass that measured approximately 25 by 23 by 15 centimeters (9.8 by 9.1 by 5.9 inches), extending from epigastrium [just above the stomach] to upper pelvis," the medical team wrote in their case report.

"It was showing fat density areas, soft tissue and multiple calcified density components of various sizes and shapes resembling the shape of vertebrae, ribs and long bones. This mass was causing displacement and compression of adjacent abdominal viscera."

The discovery of vertebrae, ribs, and fat led doctors to diagnose the teenage patient with fetus in fetu (FIF), before scheduling the teen in for surgery, Science Alert reports. 

The case study describes how the doctors removed a horrific sounding mass of partially formed human from the girl's abdominal cavity.

The mass is described as being made from a "hairy cheesy material, multiple teeth and structures resembling limb buds."

An extremely rare condition

FIF is somewhat of a mysterious condition - it is not fully known how it develops. One commonly held theory states that the mass is a parasitic twin that was absorbed by a child while in the uterus. As per the case report, the condition is usually discovered in young children, and the parasitic mass rarely lives for long. This was only the eighth case of FIF found in an adult.

The condition occurs in about 1 in 500,000 live births, and less than 200 cases have been reported in the medical literature.

Thankfully, the patient is doing well, and the majority of the mass was removed. However, she will have to have annual checkups to make sure small remaining tissue - not removed so as to avoid serious blood loss - has not turned cancerous. In the case report, she is quoted as saying, "thanks to all operating doctors."