||This article needs additional citations for verification. (December 2011)|
Diphallia, penile duplication (PD), diphallic terata, or diphallasparatus, is a rare medical condition in which a male infant is born with two penises. The first reported case was by Johannes Jacob Wecker in 1609. Its occurrence is 1 in 5,500,000 men in the United States.
When diphallia is present, it is usually accompanied by other congenital anomalies such as renal, vertebral, hindgut or anorectal duplication. There is also a higher risk of spina bifida. Infants born with PD and its related conditions have a higher death rate from various infections associated with their more complex renal or colorectal systems.
It is thought 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.
See also 
- "Concealed diphallus :a Case report and review of the literature.". Journal of Indian Association of Pediatric Surgeons. Archived from the original on 2000. Retrieved 2010-03-07.
- "Indian man wants op to remove extra organ". Reuters. Archived from the original on 22 January 2007. Retrieved 2006-08-18.
- Diphallia Medical Case Report
- Man With 2 Penises, Woman With 2 Vaginas Were the Sexiest Couple of the 19th Century (contains photos with nudity)