Diphallia is a rare genetic condition that occurs when an infant is born with a duplication of the penis.

There are different types of diphallia, ranging from partial to complete penile duplication. Having two completely developed penises, or true diphallia, is very rare.

Ever since the first description of diphallia in 1609, researchers have only reported 100 additional cases worldwide. It may occur in 1 in every 5–6 million live births.

This article takes a closer look at diphallia, including its symptoms, causes, effects on a male’s life, and the possibilities for treatment.

a man sat down an contemplating his diphallia or double penis. Share on Pinterest
A person with diphallia may have a partial to complete penile duplication.

Every case of diphallia is unique, and the amount of duplication varies with each. Most males with this condition will have two penises of about the same size, located side by side.

Some males will have a larger penis located above a second, smaller penis. For others, the duplication will only affect the head of the penis.

Earlier classification described three types of diphallia:

  • a duplication of only the tip of the penis, or the glans
  • bifid phallus, wherein each penis has only one column of soft tissue (the corpus cavernosum) instead of two, as is normally the case with true diphallia
  • complete diphallia, wherein there is a complete duplication of the penis

However, current classifications claim that there are only two types of diphallia: true diphallia and bifid phallus.

Diphallia usually occurs alongside other birth irregularities. These can include:

  • a cleft scrotum
  • hypospadias, wherein the opening to the urethra is on the underside of the penis, instead of the tip
  • duplication of the urethra in both penises
  • no urethras in either penis
  • abnormal heart muscles
  • two bladders
  • a missing anus
  • atypical muscles attached to the bones
  • irregular positioning of the scrotum
  • irregularities affecting the public bone
  • misshapen, rotated, or extra kidneys
  • complications of the kidney and colorectal systems

Males with diphallia are at greater risk of spina bifida. They are also more likely to be sterile.

Diphallia is a genetic condition that comes about during the development of the fetus.

The genetic irregularity that causes diphallia takes effect during the development of the genitals.

Some researchers suggest that exposure to drugs, infections, or other damage between the 23rd and 25th day of gestation could lead to diphallia, as this is a crucial stage of fetal development.

Males with diphallia are often able to urinate through one or both penises. They may also be able to have erections and ejaculate with one or both penises.

Depending on the individual situation, males with this condition may be able to have a normal sex life and have children.

However, there tends to be an increased risk of poorly functioning kidney and colorectal systems. For this reason, infants with diphallia may have a higher risk of death due to infections.

That being said, this may not be the case when diphallia is not associated with other irregularities.

Surgery is the only treatment option for diphallia. Treatment is not always necessary, however.

A surgeon will usually perform this surgery at birth or very soon after. The procedure will vary based on how much duplication there is and the presence of other birth irregularities.

Because each case of diphallia is unique, the surgery to treat it can be complicated and difficult. The primary concerns are:

  • making sure that the male will be able to urinate normally and have erections
  • reducing the potential risk of infection
  • reducing structural irregularities

The timing of the surgery will be an important factor due to the male’s likely age. As doctors often diagnose diphallia at birth, there may need to be several surgeries over time.

Individuals with diphallia often have other birth irregularities, such as hypospadias, duplicated urethras, and cryptorchidism (wherein one or both testes do not descend). Researchers report that in many cases, surgeons can repair the physical irregularities associated with diphallia.

In one case, surgeons treated some of the infant’s irregularities soon after birth, but they only removed the additional penis when the individual was a toddler.

Males with diphallia do not always opt for treatment, as in the case of a 54-year-old male whose doctor diagnosed diphallia during an examination for a hernia. Surgeons repaired the hernia, but the patient did not deem it necessary to remove the smaller penis.

Diphallia is a rare genetic birth irregularity in which a male infant is born with duplication of the penis. This duplication can involve only the tip of the penis or result in two fully functioning penises.

When males are born with diphallia, they often have other birth irregularities as well.

Surgery is the only way to treat diphallia. Surgeons may address diphallia and additional birth irregularities in several stages.

Males with diphallia can lead full and healthy lives.