What is known as "Fetus in fetu" (FIF) It is an extremely rare condition in which the malformed fetus is found in the living twin. It is so strange that it occurs in about one in 500,000, or even one million births, and less than 200 cases have been reported in the medical literature.
The last known case is that of a 17-year-old Indian teenager who went to the doctor for a lump in her abdomen that she had begun to feel for five years, and believed that it could be a tumor. However, by removing it, doctors found that it was his twin brother who had not formed during pregnancy, and that continued to grow.
A doubly exceptional case
The case was reported in the scientific publication. BMJ Journals for its exceptionality, not only for the case itself, but for it is the first time it is detected in an almost adult woman. Most cases have been described in newborns and children and only seven cases have been reported after 15 years, all in men.
In Babies and more Rare cases of twinsIn the young woman's analysis, they found beta-human chorionic gonadotropin (β-HCG) and alpha fetus protein, hormones present in pregnancy. They also found an abdominal mass of firm to hard consistency, of irregular surface and that did not move with breathing. When performing a CT scan with contrast, it showed a well-defined mass that when removed measured 30 × 16 × 10 cm.
It also showed areas of fat density, soft tissue and multiple components of calcified density of various sizes and shapes "that they resembled the shape of vertebrae, ribs and long bones".
In addition, "multiple teeth and structures resembling the tips of the extremities" were discovered. This mass was causing displacement and compression of adjacent abdominal viscera.
"Fetus in fetu" or twin-parasite
"Fetus in fetu". Abdominal bulge of the patient. How does it happen? It is caused by a genetic error during fertilization of the ovum. Segmentation of the two cells that will give rise to fetuses does not occur as it should, causing one embryo to absorb the other during growth.
An atrophied twin that has not been formed is found inside the other twin, benefiting from fetal circulation, like a parasite. It is extremely rare to occur, but in most cases it is diagnosed in the first years of life (89% before 18 months) and even during pregnancy by ultrasound.
Generally, it is diagnosed as a tumor (called teratoma) composed of embryonic tissues that is inside the body of its twin brother.
In Babies and more A baby is born in Colombia with her twin sister inside her abdomen: a strange case of "fetus in fetu"Via BMJ
In Babies and more | A one-year-old girl is "pregnant" with her sister
