There are medical cases that surprise the researchers themselves due to their rarity. One of them has been the intervention on a one-year-old girl by a team of surgeons who have operated on her to extract her "parasitic twin brother" from her brain. Just like it sounds.
The case, described by a team of scientists from Fudan University in Shanghai, China and published in the journal Neurology, has caused quite a stir. The medical team operated on the baby "with motor delay and enlarged head circumference" who had found a "malformed diamniotic monochorionic twin".
After removing it, the scientists determined that the fetus of its twin brother had been "absorbed during gestation" in a development process known as "neural plate folding" or "neurulation," at which point the tube forms. neural - which becomes the future brain and spinal cord of the newborn - and the entire nervous system develops.
Usually, the parasitic twin appears in the abdomen. Once removed, the doctors observed that the malformed fetus had upper extremities and even finger-like projections.
This phenomenon takes place in the pregnant uterus, where the two fetuses had shared the same placenta, but in separate amniotic sacs. One of the two fetuses became "enveloped" by the other, a process known as "fetus-in-fetus."
This phenomenon occurs in one in every 500,000 births and, when it happens, in most cases the fetus stops developing.
