Diphallia, penile duplication (PD), diphallic terata, or diphallasparatus is an extremely rare developmental abnormality in which a male is born with two penises.
[4] Infants born with diphallia and its related conditions have a higher death rate from various infections associated with their more complex renal or colorectal systems.
[citation needed] It is generally believed diphallia occurs in the fetus between the 23rd and 25th days of gestation when an injury, chemical stress, or malfunctioning homeobox genes hamper proper function of the caudal cell mass of the fetal mesoderm as the urogenital sinus separates from the genital tubercle and rectum to form the penis.
[11] The current widely accepted classification, introduced by Aleem in 1972, classifies double penis into two groups: true diphallia and bifid phallus.
[1] Infants born with diphallia have higher death rate due to infections associated with anomalies.
He had imperforated anus, hypospadias, bifid scrotum, meatuses on both glandes, two bladders and two colons, and had normal testes, kidneys and ureters.
[13] This rare case was reported,[13] based on the age of the 83-year-old man when diphallia was only detected then when he was hospitalised, and also because of the absence of other anatomical malformations.
[10][15] Normal development of penis occurs with the fusion of cloacal tubercles at anterior end of urogenital sinus.
[1][12] The concept of caudal duplication syndrome is used to explain the symptoms of diphallia with associated complex anomalies in lower abdomen and urinary tract.
The cause is uncertain, but most scientists agree that diphallia is a defect of genital tubercle, and occurs at about week three of gestation, when caudal cell mass of mesoderm is affected by various external environmental factors including drugs, infections and malfunctioning homeobox genes.
[11][2] Treatment is a case-by-case analysis taking into account considerations for medical and ethical reasons, and involves surgical excision of the non-functioning penis.