Diphallia: When men are born with two penises

This condition is one that you could guess if you really thought about the Latin name. Some men are born with two distinct penises. Although the condition is extremely rare, doctors know exactly why it occurs. Learn about this rare, but regular medical phenomenon.

The first case of diphallia was reported by a physician in 1609, and since then it has been reported regularly, though not very often, in all countries and all nationalities. It's one of the traits that doesn't seem to run in families. Diphallia can come with spinal and renal problems, most cases of diphallia are otherwise healthy at birth. (Although the condition is associated with infections and renal problems due to diphallic men having a more complicated urological system.)

There are many ways diphallia can manifest itself. The most common is two identical penises side by side. Slightly less common is a smaller penis just on top of a larger one. There are even cases of a second penis being internal, meaning that only when the man underwent treatment for urological problems did he find out he had another penis. Sometimes diphallic penises are both fully functional. Men can urinate out of one or the other or both at the same time. Often, though, these men have fertility problems, because the entire genital system is re-ordered.

Although there have only been about a hundred cases since 1609, doctors do know what causes diphallia. At about the 24th or 25th day of gestation the tract that forms the urolo-genital organs separates out from both the undifferentiated developing genitalia and the developing rectum. If some special stress is put on the developing embryo on those days, the cells can form twice. Although it's a rare phenomenon, it's estimated that in the United States, one in every five and a half million men have diphallia.

Double Rainbow Image: Nicholas T

Via Princeton, Jiaps, and Reuters.