21.6 Pathology

Abnormalities of male genitalia


Quiz 18

Hypospadia is a relatively frequent disorder of the external genitalia (3:1000 births), while epispadia is a very rare anomaly (1:30'000 births) and frequently associated with other complications.


Hypospadia is the most frequent penile abnormality whereby the incidence, depending on which author is consulted, is given as being between 1 - 8 / 1000 newborn boys. A closure disorder of the urethral groove on the underside of the penis is involved.

One distinguishes various anatomic variants:

  • Hypospadia of the glans penis is characterized by a urinary meatus on the underside of the glans.
  • With a hypospadia of the penile shaft, the urinary meatus is in the middle of the penis.
  • In a hypospadia of the scrotum the fusion of the genital swellings is absent and a urethral opening at the level of the scrotum remains.
Fig. 66 - Glandular hypospadia

Fig. 67 - Penile hypospadia Fig. 68 - Scrotal hypospadia

From an embryologic point of view, hypospadias of the penis and scrotum arise from a closure disorder of the urethral groove (spongy part of the urethra) by the urethral folds or the genital swellings, going out from the urethral plate, which has an endodermal origin. The urethral groove closes in the posterior part through fusion of the genital swellings and anteriorly progressively through the closure of the urethral folds up to the glans. The urethra within the glans has an ectodermal origin. So hypospadia glandis can be traced back to a closure disorder of the epithelial lamella on the penile tip and can extend up to the navicular fossa.

The cause for this disorder is multi-factorial: besides genetic factors the damaging effects of a hormone therapy with progesterone during the first month of pregnancy also plays a role. An altered synthesis of testosterone (or its derivative) and/or an anomaly of the receptors for this hormone can also be blamed.

Under the most frequent abnormalities associated with a hypospadia are penile deviations, a stenosis of the urinary meatus and a deviation of the raphe mediana. Finally, a hypoplasia of the cavernous body, leading to a micropenis, is also not rare.

Hormone therapy (in the case of a micropenis) for stimulating growth is often combined with a surgical reconstruction of the urethra.


Epispadia is a much more rare abnormality than hypospadia and is seen in only 1 / 300'000 newborns. It also occurs in girls (1 girl: 5 boys). Here the urinary meatus is localized on the upper side of the penis or clitoris.

From an embryologic point of view this abnormality can be traced back to a disorder of the mesoderm cell migration during the 4th developmental week. Depending on how strongly affected the person is, an exstrophy of the urinary bladder together with epispadia or only an isolated epispadia results.

More info

This site (french) shows the clinical aspects of exstrophy of the bladder and epispadia

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