...Another
important distinction to be made is whether or not the undescended
testes are palpable. An impalpable testis may be a true intraabdominal
or intrapelvic gonad, it may be a testis that is intermittently passing
in and out of a large patent processus vaginalis, it can be canalicular
or completely absent ( vanishing testis) caused by atrophy secondary
to antenatal torsion (5). If testicular agenesis or dysgenesis is
the cause, the contralateral testis undergoes compensatory hypertrophy
with increased volume usually noted by ultrasonographic measurements
(14). Contralateral hypertrophy predicts monorchia with 90% accuracy
(16). If a testis cannot be palpated along its normal line of descent,
one must look for it in common ectopic sites such as the femoral region,
perineum, retropubic region, base of the shaft of the penis or even
in the contralateral scrotum, a condition referred to as transverse
ectopia (5). If not felt in any of these sites, the entity is labelled
" impalpable testis" (10).
During physical examination, one should also look
look for signs suggestive of syndromes associated with cryptorchidism,
namely, Prune Belly, Noonan, Prader-Willi, Kallman's, Lawrence-Moon-Biedel
and Arthrogryposis Multiplex Congenita. The genitalia should be examined
for evidence of hypospadias or ambiguity. Hypospadias and undescended
testes are commonly associated with a state of intersexuality specially
"mixed gonadal dysgenesis" and "true hermaphroditism".
A phenotypically male newborn with confirmed bilateral impalpable
testes should be considered a genetic female with "congenital
adrenal hyperplasia" until proven otherwise (10).
The examining hands should be warm in order not to induce ascent by
triggering the cremasteric reflex ( 5,10).
Laboratory Studies.
Serum studies include testosterone, LH, FSH and MIS. In nonpalpable
testes, HCG challenge test with monitoring of testosterone levels
will help differentiate agenesis from maldescent. An increase in
testosterone levels indicates presence of the testes somewhere.
A negative HCG challenge and elevated gonadotropin LH, FSH are definite
hormonal evidence of testicular absence and may preclude surgical
exploration. Normal LH and FSH levels or a detectable MIS level
warrant surgical exploration even if the HCG challenge is negative.
Some also recommend measurement of thyroid hormone and cortisol
levels since hypogonadism can be due to pituitary aplasia (10,11).
Radiologic Imaging.
Ultrasound is helpful in infants with bilateral non-palpable testes
to exclude the presence of a uterus thus ruling out congenital adrenal
|
hyperplasia. It is also helpful in overweight children to detect
inguinal testicles that are difficult to palpate. CT and MRI are
not warranted because they are neither sensitive nor specific. CT
exposes the testes to radiation. The gold standard remains open
surgical or laparoscopic exploration (5,10).
Management
A
neonate diagnosed with undescended testes should be followed up
till six months to one year of age. If by then the testes do not
descend, it is almost definite that they will never descend spontaneously
and management becomes warranted (10). Some studies that if testes
do not descend by the age of three months, the chances for spontaneous
descent are rare (10).
The
aims of management are to enhance fertility, repair concomitant
hernias, reduce the incidence of trauma to the testis, make the
testis easily accessible to examination for detection of testicular
cancer, and for psychological and cosmetic considerations (11).
The
optimal age of surgery is between the ages of six months and two
years. The only problem associated with surgery at this age is the
significant risk of injury to the spermatic vessels and thus the
need for an experienced surgeon.
For
palpable testes there are two modalities of treatment: hormonal
and surgical.
Hormonal: Administration
of testosterone is minimally effective because testicular descent
depends on the paracrine effect of testosterone. However, using
gonadotropins to stimulate the testes to produce testosterone may
help patients achieve high levels of testosterone locally (10).
Intramuscular HCG has also been used successfully (17), however,
GnRH and gonadotropins are considered to be more effective and most
commonly used (10).
The
best success of hormonal therapy has been in low undescended testes,
achieving rates of 10% to 50%. High undescended testes are very
unlikely to respond to hormonal therapy and even if they respond
and descend, they will ascend to their original place after hormonal
withdrawal (1). HCG is sometimes used preoperatively to increase
the size of the testis and render it easier to palpate and identify
(17).
The
side effects of hormonal therapy include enlargement of the penis,
increased pubic hair growth, increased testicular size and aggressive
behavior during administration (10).
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