You may not know that all of us had tails while in our mother’s womb. Specifically, between the 4th and 8th weeks of gestation, the human embryo develops a tail at the coccyx as a genetic remnant left by our ancestors.
However, from the 6th to the 12th week, white blood cells will destroy these tails (they consume the cells here and absorb the tail back) because evolution suddenly remembers that humans no longer need tails.
Nevertheless, if for some reason nature was forgetful, the fetus will continue to develop past the 12th week and still retain its tail. The child will then be born with an intact tail, which can even grow longer as they grow up.
Recently, Brazilian doctors reported such a case in the journal Surgery Case Reports. A newborn boy was born with a 12 cm long tail remaining on his left buttock. Moreover, the tip of the tail has a round mass that makes it look like the tail of the cartoon character Doraemon.
“A human tail is classified as either a true tail or a pseudo-tail. A true tail represents the existence of a remnant embryonic tail… formed from fatty tissue, connective tissue, blood vessels, muscles, and nerve fibers“, the doctors at Albert Sabin Children’s Hospital in Brazil stated.
Meanwhile, a pseudo-tail refers to abnormal protrusions at the coccyx, which may be caused by deformities or spinal bifida. Pseudo-tails are therefore more common while modern medical literature has only recorded 40 cases of children born with true tails.
In some places around the world, children born with tails often face stigma and rejection. In contrast, in certain areas such as India, tails are considered a blessing or a gift from the gods.
Returning to the Brazilian boy, the doctors confirmed that his tail is a true tail. The ultrasound results showed that it has no neural connections with the spine. The tail also lacks bones or cartilage. It is merely a structure of fatty tissue, muscle, and nerve connective tissue with large blood vessel branches.
The 12 cm long tail has a spherical mass with a diameter of 4 cm at the end. This ball resembling Doraemon’s tail has been identified as a fibrous tissue containing collagen. Despite its large size, during all 8 prenatal consultations, including ultrasounds for the mother, the doctors did not detect this tail at all.
The mother reported that during her pregnancy, she was completely healthy except for a urinary tract infection that required her to take antibiotics. However, she had a bad habit of smoking, and during the pregnancy, she still smoked about 10 cigarettes a day.
The mother’s smoking is not directly related to causing the fetus in her womb to have a tail, but it seems to have some impact, leading to the boy being born prematurely at 35 weeks of gestation.
Nevertheless, aside from the strange tail and jaundice, the doctors reported that the boy was quite healthy. They assessed the boy’s tail and advised the mother to consider having it removed.
This is because growing up with such a tail can often be quite inconvenient. There are no signs that this tail could provide any function for the boy. In contrast, those who have kept their tails as they grew up reported that it caused pain, inconvenience, and discomfort.
The tail prevented them from wearing pants and sitting normally, as putting pressure on it could cause pain. Some individuals have kept their tails until the age of 17 but eventually had to have them removed because they could no longer tolerate it.
The doctors at Albert Sabin Children’s Hospital stated that after performing the tail removal procedure, the boy experienced no complications and is completely healthy. They reported this case in a medical journal to provide other doctors with an overview of rare cases of individuals with true tails, while also warning that pseudo-tail cases should be screened and detected early during pregnancy.
“Due to the common ectodermal origin between skin and the central nervous system, it is essential for pediatricians or pediatric surgeons to investigate the presence of potential spinal dysfunction in patients suspected of having lesions, as these may be the only visible abnormalities and can be diagnosed early“, the research team wrote.
Reference: Sciencedirect