The testicle begins to form just before the second fetal month and starts to
look like a testicle around the fourth fetal month. By then it has migrated
down from the kidney and lies next to the internal inguinal ring, where it
remains until around the seventh fetal month. At this point the testicle, accompanied
by a small peritoneal tube (the so-called hernia sac), passes through internal
ring, inguinal canal, and external ring to take its normal position in the
Not all mammals have testicles that lie outside the main abdominal cavity. In
humans, however, this location seems necessary for future fertility in that
the scrotum keeps the testicles 2 to 3 degrees C. cooler than the core body
temperature. This temperature difference seems important for the development
of normal postpubertal testicular structure as well as for production of fertile
sperm. There are other advantages to a location within the scrotum. There is
a cosmetic advantage. The scrotal testis may be less amenable to injury than
a testis outside the scrotum in that the latter may be anchored in position
directly over bone. Finally, and perhaps as important as any other reason,
a testis that has not made it into the scrotum is not accessible to physical
examination. This is a serious handicap because the most common solid tumor
in males after puberty and up to age 40 years is testicular cancer. Testicular
carcinoma is highly curable, when detected early, and the best way to do this
is monthly self-examination -- which is only feasible in testes that lie within
The term "undescended testicle" is loosely applied
to several different conditions. When a testicle is not in the
normal scrotal location several possibilities
- There may never have been a testicle (congenital absence=agenesis).
This is the least likely possibility and is only occasionally associated
with an absent kidney on that same side.
- The testis may have been lost before or just after birth due to torsion
or vascular accident involving the testicular vessels.
- The testis may have not descended properly, but remains within the
abdominal cavity. In older children, such abdominal testicles are abnormal
in appearance, are not likely to be fertile, and have an increased
chance of becoming malignant after puberty.
- The testis may have descended incompletely and may lie within the
inguinal canal, at the external ring, or just outside of the scrotum.
- The testis may have come through the inguinal canal, but instead
of then traveling down into scrotum, the testis passes into an ectopic
location (usually a space under the skin in the groin, called the superficial
pouch) where it is firmly anchored to the adjacent tissues. Unusual
ectopic sites include the femoral region or the perineum.
- Retractile testes that temporarily get pulled up into the groin by
hyperactive muscles may be confused with situations #4 or #5. However,
retractile testes rarely are a clinical problem and generally require
A testicle that is not in the
normal scrotal location should be located and if fairly normal,
should be placed in a normal position. When a testis is felt
in the superficial pouch or inguinal canal we usually explore the area
with a small hernia-type incision. Usually the testis will look
suitable for salvage
and can be delivered into the scrotum and anchored in a subcutaneous
scrotal pouch (orchidopexy). Most undescended or ectopic testes
are accompanied by
a hernia sac that must be separated from the spermatic cord, divided,
and closed. Sometimes this is the most difficult part of the
operation. When a testis cannot
be felt by physical exam, we look for it with a laparoscope at the time
of surgery. Depending upon what is found by the laparoscope we
will usually bring
down a salvageable testis (orchidopexy) or remove a very abnormal gonad
(orchiectomy). When a boy is left with a single functioning testis
we recommend anchoring
it to minimize chances of losing it to torsion later in life. (The primary
causes of testicular loss during childhood are trauma and torsion. Anchoring
the testis, we believe, lessens the chance of late torsion. We furthermore
advise use of a protective cup should the child become active in contact
The usual complications of testicular surgery are bleeding and infection.
Transfusion is very unlikely in these patients and infections are uncommon
and usually involve only the sutures at skin level. One cannot promise
fertility for any male child, and the undescended testis -- no matter
how it is managed surgically -- is less likely to be fertile than a
normal testis. Still, early orchidopexy should optimize the chances.
Occasional boys will have unusual postoperative pain or prolonged ileus
(intestinal shutdown) with inability to eat. The overwhelming majority
are eating and comfortable the day after operation. We have suggested
putting away bicycles and similar toys for 6 weeks after orchidopexy
because we have seen a few boys with dislocated testes after orchidopexy
or similar operations. We have speculated that a vigorous straddle
injury might pop a testis back into the external ring area where it
is entrapped by the healing tissues. In spite of the most careful anchoring
procedures, late torsion has been reported in some boys after orchidopexy.
Any male can develop a testicular tumor, and boys with undescended testes (even
after orchidopexy) have a higher than average risk. The chance of cancer (carcinoma
in situ and overt carcinoma) in men who have had orchidopexy may be 8% or more
according to recent data. Monthly self-examination of the testes should be
taught and encouraged after puberty for all males. With routine self-exam the
normal anatomy will become appreciated and subsequent development of a nodule
or hardening will ideally be detected very early. With early treatment testicular
cancer is usually curable.
Follow-Up After Treatment Of Undescended Testis
We generally see orchidopexy patients first a few weeks and then a few months
after their operations. If anything unusual is observed at any other times
we ask the families to contact us or bring the child right in to Pediatric
Walk-In at the University of Michigan Emergency Room and we will see you there.
In addition, we have asked the families to let us see the patient around the
time of puberty so we can assess growth of the testis and be certain that it
is not in jeopardy from, say, a varicocele or some other problem. Most importantly,
we would use this occasion to discuss self-exam with the patient to try to
initiate this in each youngster's personal routine.