Having two extra penises, known as triphallia, has only been seen once before, in a newborn baby some years ago.

A man has been discovered to have two extra penises by medical students dissecting his body, marking only the second time ever someone has been found to have three penises.

This incredibly rare triple penis phenomenon was found by students at the University of Birmingham Medical School in the U.K. during a dissection of a 78-year-old man who had donated his body to science, according to a new paper in the publication Journal of Medical Case Reports.

According to the researchers, the man may never have known he had three penises.

This condition, known as triphallia, was only seen in a human for the very first time in 2020 in a newborn, and is thought to affect one in every 5 to 6 million live births.

“Triphallia, a rare congenital anomaly describing the presence of three distinct penile shafts, has been reported only once in the literature,” the researchers wrote in the new paper. “Without dissection, this anatomical variation would have remained undiscovered, suggesting the prevalence of polyphallia may be greater than expected.”

Having two penises, known as diphallia, has been seen in around 100 human cases, and occurs once in every 5.5 million live births. Usually, doctors remove the extra penises at birth if they are externally visible, but they are often left alone or go unnoticed entirely if hidden inside the body.

The 78-year-old man appeared to have normal genitals externally, but once his penis was dissected, the students discovered two other tiny duplicate penises hidden inside his scrotum.

  • Snothvalpen@lemmy.blahaj.zone
    2·
    2 months ago

    Any smart heads that can tell me how fidning 2 cases of something gives enough of a clue that this might occur as often as 1 in 5-6 million live births?

    • I_am_10_squirrels@beehaw.org
      4·
      2 months ago

      Populations tend to follow normal distributions. This was first studied by a scientist working for Guinness brewery. He wanted to share his work without revealing his employer, so he published under the pseudonym Student. This is where we get the student’s t test.

      Anyways, statistics math is complicated but you can make some inferences about prevalence based on a small sample by assuming normal distribution.

    • Tarquinn2049@lemmy.world
      3·
      2 months ago

      I would imagine it’s estimated from the type of mutation and the math involved of how common that class of mutation tends to be. Like how many genes have to change randomly and the chances of each one happening on average, multiplied together. The odds could be similar because the same genes are involved and only one of them controls the difference between 2 and 3, and the odds of it being 3 aren’t that much more rare, but 3 would be more likely to go undiscovered because the odds of them lining up with the scrotum and being small enough to be completely obscurred externally are significantly higher. So then they are only discovered if there is any reason to look inside the scrotum. Most dead bodies don’t get examined, not like on TV. And even if they do, the odds of their being any reason to look inside the scrotum are pretty low.

      So there could be just as many people that have had it, but none ever knew.

    • nezrock@lemmy.dbzer0.com
      2·
      2 months ago

      Yeah, and if diphalia occurs at roughly the same rate (1 in 5.5 million), why is it 50x as common, and why, given the rate, wouldn’t there be over a thousand people with the condition alive today?

      • Tarquinn2049@lemmy.world
        6·
        2 months ago

        Most important difference, when there is 2, they appear in a pair side by side, and are generally both visible. When there is three, the middle one is in the place you would expect and the other two tend to grow much smaller and inside the scrotum. Not likely to ever have any reason to look for penises in there. For all you know, you could have it. Assuming you have at least one penis you know of currently, that is. And even if you do have 3, you will likely never know. And even after you die, there is a very low chance anyone will find out. Very few bodies get autopsies or donated to science. And even if you do, there is not much reason to look inside a scrotum either way.