Sandbox MWH

Cryptorchidism

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Muhammad Waleed Haider, M.D.[2]

Synonyms and Keywords: Cryptorchism; maldescended testis; ectopic testis; undescended testicle

Historical Perspective

Cryptorchidism is derived from the Greek words "crypto" (meaning "hidden") and "orchid" (meaning "testicle"). During the last century, cryptorchidism was sometimes restricted to the subset of undescended testes that were not palpable above the scrotum or in the inguinal canal — those that were truly hidden in the abdomen or completely absent. In recent decades the distinction is no longer made in most contexts, and the two terms are used interchangeably. Cryptorchism is an older variant of the same term.

Pathophysiology

The testes begin as an immigration of primordial germ cells into testicular cords along the genital ridge in the abdomen of the early embryo.

A testis absent from the normal scrotal position can be:

• Found anywhere along the "path of descent" from high in the posterior (retroperitoneal) abdomen, just below the kidney, to the inguinal ring
• Found in the inguinal canal
• Ectopic, that is, found to have "wandered" from that path, usually outside the inguinal canal and sometimes even under the skin of the thigh, the perineum, the opposite scrotum, and femoral canal
• Found to be undeveloped (hypoplastic) or severely abnormal (dysgenetic)
• Found to have vanished (also see Anorchia)

About two thirds of cases without other abnormalities are unilateral; 1/3 involve both testes. In 90% of cases an undescended testis can be palpate (felt) in the inguinal canal; in a minority the testis or testes are in the abdomen or nonexistent (truly "hidden").

Associated Conditions

Cryptorchidism occurs at a much higher rate in a large number of congenital malformation syndromes. Among the more common are:

• Cloacal exystrophy
• Noonan syndrome
• Prader- willi syndrome

Causes

In most full-term infant boys with cryptorchidism but no other genital abnormalities, a cause cannot be found, making this a common, sporadic, unexplained (idiopathic) birth defect.

Rare iatrogenic cases have also been reported in which hernia repair or other surgery in the inguinal area resulted in trapping of a testis above the scrotum.

A 2006 study showed that regular alcohol consumption during pregnancy (5 or more drinks per week) is associated with a 3x increase in cryptorchidism, when compared to non-drinking mothers. Other previously known risk factors include exposure to pesticides, low birth weight (including premature birth), gestational diabetes and being a twin.

Diagnosis

History and Symptoms

• There are usually no symptoms, except that the testicle cannot be found in the scrotum (this may be described as an empty scrotum).

Physical Examination

The most common diagnostic dilemma in otherwise normal boys is distinguishing a retractile testis from a testis that will not/cannot descend spontaneously into the scrotum. Retractile testes are more common than truly undescended testes and do not need to be operated on. In normal males, as the cremaster muscle relaxes or contracts, the testis moves lower or higher ("retracts") in the scrotum. This cremastaric reflex is much more active in infant boys than older men. A retractile testis high in the scrotum can be difficult to distinguish from a position in the lower inguinal canal. Though there are various maneuvers used to do so, such as using a crosslegged position, soaping the examiner's fingers, or examining in a warm bath, the benefit of surgery in these cases can be a matter of clinical judgement.

Treament

Medical Therapy

Hormone treatment does have the occasional incidental benefits of allowing confirmation of Leydig cell responsiveness (proven by a rise of the testosterone by the end of the injections) or inducing additional growth of a small penis (via the testosterone rise). Some surgeons have reported facilitation of surgery, perhaps by enhancing the size, vascularity, or healing of the tissue. A newer hormonal intervention used in Europe is use of GnRH analogs such as nafarelin or buserelin; the success rates and putative mechanism of action are similar to hCG, but some surgeons have combined the two treatments and reported higher descent rates. Limited evidence suggests that germ cell count is slightly better after hormone treatment; whether this translates into better sperm counts and fertility rates at maturity has not been established. The cost of either type of hormone treatment is less than that of surgery and the chance of complications at appropriate doses is minimal. Nevertheless, despite the potential advantages of a trial of hormonal therapy, many surgeons do not consider the success rates high enough to be worth the trouble since the surgery itself is usually simple and uncomplicated.

Surgery

The primary management of cryptorchidism is surgery, called orchidoepxy. It is usually performed in infancy, if inguinal testes have not descended after 4-6 months, often by a pediatric urologist or pediatric surgeon, but in many communities still by a general urologist or surgeon.