Undescended testes (cryptorchidism) in children and adolescents

DEFINITIONS

Cryptorchidism by definition suggests a hidden testicle: a testicle that is not within the scrotum and cannot be manipulated into the scrotum by several months of age (picture 1). Cryptorchid testicles are absent or undescended. An absent testicle may be due to agenesis or to intrauterine vascular compromise (eg, torsion). Boys who have bilaterally absent testicles have anorchia.

Most cryptorchid testicles are undescended. True undescended testicles have stopped short along their normal path of descent into the scrotum (figure 1). They may remain in the abdominal cavity or they may be palpable in the inguinal canal or just outside the external ring (canalicular and suprascrotal, respectively) [1].

Ectopic testes descend normally through the external ring but then are diverted to an aberrant position [2]. They may be palpable in the superficial inguinal pouch (most common), suprapubic region, femoral canal, perineum, or contralateral scrotal compartment (least common) (figure 2) [3,4]. Testes occasionally are noted to be in a scrotal position in early childhood and then to "ascend" and become undescended [5-7]. Ascending testicles probably represent ectopic testes that have enough laxity to reach the scrotum in early childhood, but become tethered in place and pulled out of the scrotum as the child grows [5,6,8].

Retractile testes are suprascrotal testes that can be brought into a dependent scrotal position and will remain there if the cremasteric reflex is overcome.

EPIDEMIOLOGY

Cryptorchidism can affect one or both testes; approximately 10 percent of cases are bilateral [3]; among the unilateral cases, a left-sided predominance exists [9]. The most common location for an undescended testicle is just outside the external ring (suprascrotal), followed by the inguinal canal, and finally the abdomen [10].