Editing Testis mal-descent


Occurs when the testis is arrested in some part of its normal path to the scrotum

* Differentiate from ectopic testis - abnormally placed outside this path

== Incidence ==

* About 4% of boys have one or both incompletely descended at birth
* 2/3 of these reach the scrotum during first three months
* Full descent after first three months is uncommon
* Overall incidence of testicular mal-descent at 1 year is 1%

== Pathology ==

* More common on the right
* Bilateral in 20% of cases
* May be:
** Intra-abdominal (usually lying extraperitoneal, just inside the internal ring)
** Intra-canalicular - may or may not be palpable
** Extra-canalicular - scrotal neck
** Ectopic - commonly superficial inguinal pouch (just inferior and medial to the superficial ring), femoral triangle, root of penis, or perineum
* Testis is usually macroscopically normal in early childhood but typically smaller by puberty than normal boys
* Microscopic changes apparent from 1-2 years of age (higher testis has higher degree of change)

== Consequences ==

* Impaired fertility - paternity rates around 2/3 normal if unilateral and 1/3 normal if bilateral
* Malignancy - 5-10x greater cancer risk than normal, most commonly seminoma. Unclear whether early orchidopexy removes this risk.
* Hernia - patent processus vaginalis in 90%
* Testicular torsion - higher risk

== Examination ==

* Key question is whether this is retractile or undescended - retractile testis can be gently milked down and require no treatment
* Need a relaxed boy in a warm room and supine position
* Check for scrotum development - in undescended testes, it should be underdeveloped, while in retractile testes, it is generally normal

== Treatment ==

* Orchidopexy should be performed before the age of 12 months
* Performed through a short incision over the deep ring
* Mobilise the testis down to scrotum and secure in a pocket between dartos muscle and skin
* Ligate and divide processus vaginalis , coverings of spermatic cord and fibrous bands at level of internal ring
* Sometimes a two-stage procedure is necessary
* Consider orchidectomy if the testis is later found to be atrophic

[[Category:Urology]]