A boy born with two penises had to have one removed - and doctors chose to take off the larger one.
The child from Brazil was one of the rare infants born with a second appendage, and its removal was documented in a new medical journal report.
The condition - called diphallia - is typically seen in one in a million babies, and doctors in Sao Paulo say only 100 men have been reported with the condition in medical literature.
The first reported case appeared in medical literature in 1609.
The report, featured in the Journal of Pediatric Urology, detailed that the boy's two penises lay side by side.
While some people with the condition have only an "accessory" penis or stump, this boy had "complete" diphallia.
The boy was two years old when doctors removed his second penis, but it's unclear from the medical journal report why the procedure was delayed.
Initially, doctors were planning to remove the smaller member - as both very visibly similar.
But as the boy could only urinate from the smaller penis, according to his mother, they decide to remove the other one.
The report stated that the decision was ultimately made on "functionality and not on size".
The procedure was filmed, and published alongside the journal report.
After it was removed, the remaining skin was stitched together, and the operation appears to have been hailed as a success.
The report says he only has one, rather than two, erection chambers in the remaining penis and it's unclear how it will function in future.
Elsewhere in the world, doctors in Uzbekistan have detailed the case of a seven-year-old boy with two fully functioning penises, with urethras and erectile tissue.
It is understood that men with duplicate penises can still have normal sex lives and children.
However, according to MedicalNewsToday, there tends to be a higher risk of dysfunction in the kidney systems.
It is also associated with a higher risk of spina bifida, a developmental condition that can affect the spine.
This is why medics will typically remove one of the penises, and correct any internal physical dysfunction.
The genetic irregularity that causes diphallia takes effect during the development of the genitals.
It has been posited that drugs, infections, or other damage between the 23rd and 25th day of gestation could lead to the condition.
Surgeons have previously detailed how one man's butt and penis were doing the opposite jobs for two years, before being resolved by doctors.
Indy100 has also reported in the past on a man who ended up suing his doctor for chopping three inches off his penis.
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