A MAN may have lived his whole life without ever realising he had three penises due to an ultra-rare condition.

The 78-year-old British man donated his body to the University of Birmingham Medical School, where students discovered a "remarkable anatomical variation" as they dissected him.

The man's genitals appeared normal from the outside, but further examination revealed he had two more small penises "stacked" inside his groin.

Medics described their "serendipitous discovery" in a paper submitted to the Journal of Medical Case Reports.

According to the report, the man had triphallia, "a rare congenital anomaly describing the presence of three distinct penile shafts".

Being born with more than one penis - known as polyphallia - is "extremely rare", researchers stressed.

The condition only effects on in five to six million live births.

Papers published between 1606 and 2023 contain a smattering of reports of diphalia, when someone has two penises.

But triphalia has only been reported on once before, in a 3-month-old child who had extra glans growing out of the root of his penis and his scrotum.

This makes the 78-year-old man only the second known person to have been born with three members.

What makes his case unusual is the fact that the penises were "concealed within the scrotal sac", so his genitals appeared normal from the outside.

This probably explains why the man's triphallia wasn't spotted until after his death.

According to local policy, the identity of people who've donated their bodies and their medical history can't disclosed to researchers.

As a result, knowledge of the patient's medical history is pretty limited to what medics could discover while dissecting the body.

The man was white, in his late 70s and six feet tall.

Though his "anatomical variation" may not have been flagged, it's possible that the man may have experienced urinary tract infections, erectile dysfunction or fertility issues, the report authors noted.

They found three penis-like structures stacked next to each other.

The largest was on the only member that was visible externally, while the other two were nestled in the man's scrotum .

Both of the smaller members had spongy erectile tissue - known as the corpora cavernosa - and tips.

One of the extra penises also shared an urethra - the tube the transports pee out of the body - with the primary penis.

Genital development begins in the womb and starts to happen at four to seven weeks gestation.

The report states: "The penis develops from the genital tubercule [a structure which is the precursor of the penis in males and clitoris in females] and is controlled by dihydrotestosterone.

"Genetic abnormalities affecting the expression of androgen receptors may cause morphological genital abnormalities.

"In this case, there may have been triplication of the genital tubercle.

"The urethra originally developed in the secondary penis, however, when this penis failed to develop, the urethra diverted its course and developed in the primary penis instead."

Extra members in people with polyphallia tend to be non-functional and smaller, and are often removed if they form externally.

"Without any symptoms and additional medical needs, concealed internal penises may not present themselves, preventing diagnosis," the report authors wrote.

As a result, polyphallia may be more common that we realise.

Diagnosing the condition can be especially important in clinical settings, for example when a patient needs a catheter inserted or requires surgery.

Most cases of polyphallia tend to be evident at birth due to the presence of external extra penises, or they become apparent due to symptoms like sexual dysfunction or urinary incontinence in adulthood.

"We cannot be certain that in this case the defect remained unnoticed in life," report authors wrote.

"If the defect had been noticed during his life it may have simply been left untouched due to the apparent lack of symptoms and its benign nature."