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Laurence S Baskin, MD, FAAP
Section Editor
Duncan Wilcox, MD
Deputy Editor
Melanie S Kim, MD


Hypospadias is a congenital anomaly of the male urethra that results in abnormal ventral placement of the urethral opening. The location of the displaced urethral meatus may range anywhere within the glans, the shaft of penis, the scrotum, or perineum (picture 1).

The pathogenesis, clinical manifestations, and management of hypospadias will be reviewed here.


The external genitalia in the two sexes develop from common anlagen (genital tubercle, swellings, and fold) and are indistinguishable up until seven to eight weeks gestation (figure 1).

At the ninth week of gestation, the external genitalia begin to differentiate between the two sexes:

In the male fetus, genetic programming results in androgenic stimulation that induces posterior fusion of the genital folds and growth of the genital tubercle into a phallic structure (picture 2). The penile urethra forms as a result of remolding and fusion of the medial edges of the endodermal urethral folds [1]. This involves a distal canalization of the urethral plate (opening zipper) and simultaneous fusion of the proximal urethral folds (closing zipper) (figure 2). By 12 weeks gestation, the coronal sulcus separates the glans from the shaft of the penis. By 16 to 18 weeks, urethral formation is complete, and the foreskin completely covers the glans.


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Literature review current through: Sep 2016. | This topic last updated: Jun 20, 2016.
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