Diphallus is a rare congenital anomaly occuring once in 5 million live births. The first case was reported in 1609. Neugebauer in 1898, and Nesbit and Bromme in 1933 reviewed cases in the literature3-5
Diphallus have been classified in different ways, such as glandular, bifid, concealed, complete, hemidiphallus and triple penis7,8
. Scheneider classified diphalluses in three groups; diphallia of glans alone, bifid diphallia, complete diphallia. Villanova and Raventos have added a fourth category: pseudodiphallia8,9
The urethra shows a range of variations, ranging from functioning double urethras to complete absence of urethra in each penis. The majority have a single corpus cavernosum in each phallus. The meatus may be normal, epispadic, or hypospadiac, and the scrotum may be normal or bifid. Associated congenital anomalies are present in the majority of the cases. Bladder, urethra, scrotum, uterus and vaginal duplications, bifid clitoris, anterior ectopic anus, colon, rectum and terminal ileum duplications, mental retardation, spinal anomalies, anal atresia, 11 pairs of costae, renal maldescensus, diplopodia of the left foot, intestinal malrotation, umblical hernia, ectopic bowel segment were documented in the literature7,10.
Multipl embryological explanations for diphallus exist and have been summarized by Wilson and Hollowell2,8. Almost all authors are in consensus that the anomaly is due to a defect of fusion of the genital tubercle. Hallowell et al. have suggested that it results from the failure of fusion of mesodermal bands or presentation of the oppurtunity of mesoderm to surround two urethral anlage2.
Treatment of diphallus usually includes excision of the duplicated penile structure and its urethra. Therefore, all the patients with diphallia have to be examined carefully because of the high incidence of other systemic anomalies6.