The urethral meatus (the slit men urinate and ejaculate through) is normally located at the very tip of the penis. However, sometimes during the formation of the penis during weeks 9-12 of development things can go awry and the urethral meatus develops somewhere other than at the tip of the glans. It is thought that a lack of testosterone can cause the urethra to be shorter than the penis tissue. This can lead to one of two conditions – hypospadias and epispadias.
Hypospadias occurs when the meatus surfaces on the underside of the penis or even in the scrotal area. Epispadias occurs when the meatus surfaces on the back side of the penis or on the pubic bone area.
Because the urethra is shorter, it can cause a bending or curvature of the penis towards the side where the urethra opens. This curvature is called a chordee (click HERE to learn more). Most urethral abnormalities are noticed at birth and corrected when the child is still a baby; however, they can also be corrected in older boys and even adult men who have not yet had treatment.
Hypospadias are fairly common – occurring in 1 in 200 baby boys. This can occur when the meatus (opening) is not centered at the tip of the glans. Sometimes it can be located further down the glans (glanular) or at the neck of the penis near the corona (coronal). Hypospadias can also occur on the underside of the shaft of the penis ranging from further up the penis near the neck/foreskin area (distal penile), near the middle of the shaft (midshaft) or near the base of the penis (proximal penile). In some cases, if the urethra is very short, the meatus may surface in the area where the penis and scrotum come together (penoscrotal), out of the scrotum (scrotal), or even behind the scrotum in the perineal area (perineal). [i]
If the meatus surfaces where the foreskin is located, it’s not uncommon for the foreskin to be under-developed as well and look more like a hood. Or it may appear normal and “hide” the meatus so it is difficult to locate. These boys often have a chordee or curvature that causes the penis to bend downwards.
The diagram below shows how the urethra grows inside the tissues with the different types of hypospadias:
Epispadias, on the other hand, is quite rare – occurring in less than 1 in 100,000 baby boys. Epispadias occurs when the urethra surfaces on the dorsal or back side of the penis instead of at the tip. However, unlike a hypospadias that is usually just the opening of the meatus, in an epispadias a channel will run from the opening of the meatus (often in the pubic area) all the way to the tip of the penis where the meatus should be. This can leave the penis appearing as if there is a trough. Click HERE to see an example of an epispadia.
There are three main types of epispadias based on where the urethral meatus surfaces. It can surface on the back of the glans (glanular), the penis shaft (penile) or in the pubic area (penopubic). The penises of boys/men with epispadias are almost always broad and short due to the fact that the pubic bone is spread apart, thus pulling the root of the penis inward and outward (. These boys may have a chordee or curvature that causes the penis to bend upwards. In some rarer cases, an epispadias can occur on the side of the penis rather than the back. [ii]
Surgery is the main treatment option of misplaced urethras. The goal of surgery is to create a canal that moves the meatus to the tip of the penis, correcting the curvature and any other structural abnormalities in the penis tissue and often circumcising or reconstructing the foreskin. In boys with epispadias, correction of the pelvic bone spread can lengthen the penis. In some cases, testosterone may be prescribed prior to surgery if the penis is small to help it grow larger (since it is thought that lack of testosterone caused the misplacement of the meatus and lack of testosterone leads to a shorter, less developed penis).
[i] http://www.chop.edu/conditions-diseases/hypospadias (1/14/17)
[ii] https://medical-dictionary.thefreedictionary.com/epispadias (12/27/18)
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