Undescended testes (cryptorchidism) in children: Management

INTRODUCTION — Cryptorchidism is the most common congenital abnormality of the genitourinary tract [1]. Most cryptorchid testes are undescended, but some are absent (due to agenesis or atrophy). True undescended testes have stopped short along their normal path of descent into the scrotum (figure 1). They may remain in the abdominal cavity (picture 1) or they may be palpable in the inguinal canal (intracanalicular) or just outside the external ring (suprascrotal (picture 2)) [2].

An overview of the management of undescended testes in children will be provided here. The clinical features and evaluation of undescended testes in children are discussed separately. (See "Undescended testes (cryptorchidism) in children: Clinical features and evaluation".)

TERMINOLOGY

Cryptorchidism – Cryptorchidism by definition suggests a hidden testis: a testis that is not within the scrotum and does not descend spontaneously into the scrotum by four months of age (or corrected age for premature infants) (picture 3). Cryptorchid testes may be absent or undescended.

Absent testis – An absent testis may be due to agenesis or atrophy secondary to intrauterine vascular compromise (eg, prenatal testicular torsion), also known as the "vanishing testis syndrome" or testicular regression syndrome [3]. Boys who have bilaterally absent testes have anorchia. (See "Neonatal testicular torsion", section on 'Prenatal'.)

Undescended testes – True undescended testes stop short along their normal path of descent into the scrotum (figure 1). They may remain in the abdominal cavity (picture 1) or they may be palpable in the inguinal canal (intracanalicular) or just outside the external ring (suprascrotal (picture 1)) [2].

Retractile testes – Retractile testes are normally descended testes that can be pulled into a suprascrotal position by the cremasteric reflex. These testes can be brought into a dependent scrotal position and will remain there if the cremasteric reflex is overcome (eg, by holding the testis in the scrotum for at least one minute to fatigue the cremaster muscle) [4]. (See "Undescended testes (cryptorchidism) in children: Clinical features and evaluation", section on 'Examination'.)

Ascending testes – Ascending testes are noted to be in a scrotal position in early childhood and then to "ascend" and become undescended (ie, acquired undescended testes) [5-8]. The ascent may occur at any age before puberty [9].

INDICATIONS FOR REFERRAL — Indications for referral in phenotypic males with cryptorchidism include:

●Phenotypically male newborn infants with bilaterally nonpalpable testes, unilaterally nonpalpable testis with hypospadias, or suspected difference of sex development (including congenital adrenal hyperplasia) – Immediate consultation with or referral to a multidisciplinary team (see "Management of the infant with atypical genital appearance (difference of sex development)", section on 'Initial stabilization')

●Bilateral nonpalpable testes in boys beyond infancy – Referral for exploratory surgery (as an initial step, some clinicians may perform a hormonal evaluation to exclude absent testes) (see "Undescended testes (cryptorchidism) in children: Clinical features and evaluation", section on 'Older child')

●Congenital unilateral nonpalpable testis – Referral for examination under anesthesia and exploratory surgery, ideally between 4 and 12 months of age (see 'Nonpalpable testes' below)

●Congenital palpable undescended testis (unilateral or bilateral) in infants – Referral for evaluation and possible orchiopexy, ideally between 4 and 12 months of age (see 'Palpable testes' below)

●Ascending testis in boys beyond infancy – Referral for evaluation and possible orchiopexy whenever the physical examination change is noted (see 'Timing of surgery' below)

●Palpable tissue in the scrotum that is thought to be an atrophic testis – Referral for exploratory surgery to exclude an intra-abdominal testis [10] (see 'Exploratory surgery' below)

●Difficulty differentiating between undescended, retractile, or ectopic testis (at any age) – Refer for evaluation and possible orchiopexy if beyond four months of age

NATURAL HISTORY — Most testes that are undescended at birth complete their descent within the first three to four months of life [11]. Spontaneous descent in term infants is rare after four months of age [12,13].

The growth of a unilaterally undescended testicle may be impaired compared with the normally descended contralateral testicle, whether the undescended testicle descends spontaneously or is surgically corrected [14]. Treatment before one year of age may be associated with partial catch-up growth [15]. (See 'Timing of surgery' below.)

In testes that remain undescended, changes related to fertility may occur by one year of age, as illustrated by the following observations from testicular biopsies of undescended testes performed at the time of orchiopexy [16-24]:

●The normal transformation of the fetal gonocyte into the adult dark-type spermatogonia (which usually occurs by four months of age) was impaired; fetal gonocytes persisted and then underwent degeneration.

●Germ cell density decreased over time, evident as early as one year of age.

●Spermatogonia were absent in 30 to 40 percent of undescended testes at two years of age.

●In boys with unilateral cryptorchidism, primary spermatocytes failed to appear in the undescended testis and were present in only 19 percent of the contralateral testicles at four to five years of age.

●Spermatogenesis was absent in most post-pubertal unilateral abdominal testes.

These observations suggest that, to the extent that orchiopexy alters these fertility-related changes, it may be best performed before they occur, ideally as soon as possible after four months of age [25,26]. (See 'Timing of surgery' below.)

COMPLICATIONS AND SEQUELAE — Complications and sequelae of undescended testes and associated conditions include inguinal hernia, testicular torsion, testicular trauma, subfertility, and testicular cancer. The potential seriousness of these complications and sequelae supports early referral for definitive treatment. (See 'Indications for referral' above and 'Management of undescended testes' below.)

Inguinal hernia — As many as 90 percent of congenital true undescended testes have an associated patent processus vaginalis [27-29]. In boys with untreated undescended testis, inguinal hernia can present at any time with the typical symptoms or complications, including incarceration. (See "Inguinal hernia in children", section on 'Clinical features and diagnosis'.)

The management of inguinal hernia is discussed separately. (See "Inguinal hernia in children", section on 'Initial management'.)

Testicular torsion — Testicular torsion is estimated to be 10 times more common in undescended than in normal scrotal testes, but the true relative risk is not known [30-33]. Torsion of an undescended testis is a surgical emergency. The rate of salvage of torsion in cryptorchid testes is decreased compared to that in normally descended testes, perhaps related to delay in diagnosis [30,33,34]. Early diagnosis and surgical treatment of cryptorchidism with orchiopexy may prevent testicular torsion.

Testicular torsion can occur at any age. Torsion of an undescended testis may occur in the setting of testicular tumor, presumably caused by increased weight and distortion of the normal dimensions of the organ [35]. (See "Neonatal testicular torsion" and "Causes of scrotal pain in children and adolescents", section on 'Testicular torsion'.)

Clinical findings of torsion of a cryptorchid intracanalicular testis may include inguinal swelling with or without tenderness with an empty ipsilateral hemiscrotum [31,34]. In males with these findings, ultrasonography is of limited value and should not delay surgical consultation. Torsion of an intra-abdominal testis can present as an acute abdomen, with the diagnosis of torsion made only at the time of abdominal exploration [36-38].

Testicular trauma — Undescended testes that remain in the inguinal canal are at increased risk for blunt traumatic injury because of the potential for compression against the pubic bone.

Subfertility — Men with a history of undescended testes (including ascending or acquired undescended testes) have an increased incidence of lower sperm counts, sperm of poorer quality, and lower fertility rates than men with normally descended testes [39-42]. Impaired spermatogenesis in the undescended testis probably is related to underlying genetic, hormonal, and developmental abnormalities, some of which may be partially reversible through early surgical intervention. Sperm counts in adulthood are directly related to prepubertal germ cell counts and types of testicular cells (gonocyte versus adult dark spermatogonia) at the time of orchiopexy [43-45]. (See 'Natural history' above and 'Timing of surgery' below.)

The degree of germ-cell dysfunction increases with bilateral involvement and with increasing duration of suprascrotal location [22,26,46-51]. Intra-abdominal and intracanalicular undescended testicles are affected similarly [52], probably related to the damaging effect of higher temperatures outside the scrotum on spermatogenesis [53,54].

Elevated follicle stimulating hormone (FSH) concentration and decreased serum inhibin B concentration are endocrinologic markers of Sertoli cell/seminiferous tubule dysfunction. In most studies of men with a history of cryptorchidism, Sertoli cell/seminiferous tubule function (spermatogenesis) is impaired, but Leydig cell function (virilization) is not [49,55-58]. (See "Approach to the male with infertility".)

In a cohort study, men with unilateral cryptorchidism who underwent orchiopexy by age two years had higher inhibin B and lower FSH concentrations than those who underwent surgery later in life, suggesting that orchiopexy before age two years may have beneficial effects on fertility [59]. Other observational studies suggest that orchiopexy after age one to two years (and before age 12 years) has little effect on fertility potential [46,51,60,61]. Taken together, these observations suggest that early orchiopexy is advantageous to fertility preservation.

Testicular cancer — Men with a history of undescended testis have an increased risk of developing testicular cancer compared with men in the general population in whom the age adjusted incidence is approximately 5.4 per 100,000 [62]. However, the magnitude of increased risk is poorly quantified [1].

In a 2013 meta-analysis of nine case-control studies (including a total of 2281 cases) and three cohort studies (including more than 2 million boys), the pooled odds ratio (OR) of testicular cancer in men with a history of isolated cryptorchidism was 2.9 (95% CI 2.2-3.8) but limitations included significant heterogeneity among studies (with individual ORs ranging from 3 to 50), risk of publication bias, and overall lack of high-quality evidence [63]. In a 2023 meta-analysis of three case-control studies (including a total of 3404 cases) and three cohort studies (including 368,367 children), all of whom were treated surgically before adulthood, the pooled odds of developing testicular cancer was four times greater compared with those who did not have cryptorchidism (OR 4.0, 95% CI 2.8-5.7) [64].

The risk of developing testicular cancer is further increased in men with bilateral cryptorchidism (which may be associated with endocrinologic abnormalities or abnormal karyotype) and intra-abdominal undescended testes [1,65-67]. (See "Epidemiology and risk factors for testicular cancer", section on 'Cryptorchidism' and "Clinical manifestations, diagnosis, and staging of testicular germ cell tumors", section on 'Cryptorchidism'.)

A history of cryptorchidism is also a risk factor for developing germ cell neoplasia in situ (formerly called intratubular germ cell neoplasia of unclassified type [68]), a premalignant condition. (See "Testicular germ cell neoplasia in situ", section on 'Cryptorchidism'.)

Surgical repositioning of the testis (orchiopexy) before puberty appears to decrease the risk of testicular cancer but does not completely eliminate it [1,69-72]. In a cohort of 16,983 men who underwent orchiopexy between 1964 and 1999 and were followed for a total of 209,984 person-years, 56 cases of testicular cancer were identified [69]. Among those who were treated before 13 years of age, the RR of testicular cancer compared with the general population was 2.2 (95% CI 1.6-3.1). Among those who were treated at ≥13 years of age, the RR was 5.4 (95% CI 3.2-8.6). These findings support those of several smaller case-control and cohort studies [65,73-76]. (See 'Timing of surgery' below.)

Testicular malposition is not the only factor in the development of testicular cancer in men with a history of cryptorchidism because surgical repositioning does not completely eliminate the risk. In addition, in a meta-analysis of 12 observational studies of 199 testicular tumors in men with unilaterally undescended testis, 21 percent of the tumors occurred in the normally descended testis [77]. (See "Epidemiology and risk factors for testicular cancer", section on 'Risk factors'.)

MANAGEMENT OF UNDESCENDED TESTES

Overview — The goal of management is to place and fix viable undescended testes in a normal scrotal position or to remove nonviable testicular remnants. Scrotal positioning reduces the risk of torsion and blunt traumatic injury (for intracanalicular testes) and permits easier examination of the testis. If performed sufficiently early, surgical correction may also reduce the risk of infertility and testicular cancer. Finally, having the testis in a normal, dependent scrotal position may improve body satisfaction, although the psychological impact of abnormal testicular position has not been studied.

Treatment for undescended testes is almost always surgical. Historically, hormonal therapy has been tried before surgery but has not proven to be efficacious in inducing testicular descent. Some centers use hormonal therapy as an adjunct to surgical therapy to improve fertility. (See 'Hormonal treatment' below.)

Surgical treatment

Timing of surgery — Surgical treatment of undescended testes is recommended as soon as possible after four months of age for congenitally undescended testes and definitely should be completed before the child is two years old (ideally before one year) [25,78-82]. In children with testicular ascent later in childhood, surgery generally should be performed within six months of identification.

Spontaneous descent rarely, if ever, occurs after four months of age [12,83]. Treatment of congenital undescended testes before two years (ideally before one year) of age is associated with improved testicular growth and fertility potential [46,51,59-61]. (See 'Natural history' above and 'Subfertility' above.)

In a randomized trial, 149 boys with unilateral palpable undescended testis were assigned to orchiopexy at nine months or three years of age [14,15,18,84]. At 12, 24, 36, and 48 months of age, testes in the nine-month group were larger and had greater increase in size compared with baseline than testes in the three-year group [15,84]. No significant growth was noted in the three-year group [15]. Testicular biopsies demonstrated a decline in the number of germ and Sertoli cells between nine months and three years [18]. (See 'Subfertility' above.)

Treatment of undescended testes before puberty also may reduce the risk of testicular cancer, permit earlier detection of testicular masses, and prevent testicular torsion. (See 'Testicular cancer' above and 'Testicular torsion' above.)

Palpable testes

Orchiopexy — Orchiopexy is a well-established surgical procedure for repositioning undescended or ectopic testes that are palpable [85,86]. The testis and cord are freed from surrounding attachments, and the testis is manipulated into the scrotum and sutured in place. The procedure is performed through an inguinal and/or scrotal incision. Primary orchiopexy is possible if the testis is of normal size and appearance and the testicular vessels are of adequate length [86].

In a 2012 systematic review, the average success rate for primary orchiopexy was 96 percent, with success defined by scrotal position of the testis [86]. A detailed knowledge of the retroperitoneal anatomy is required to achieve safe and adequate mobilization of the high undescended testis [87]. Thus, orchiopexy is an operation that is best performed by a surgeon with a full-time interest in pediatric urology.

Orchiopexy is safe in infants younger than one year [78,88]. The most significant complication is testicular atrophy (related to ischemic injury secondary to the dissection of the testicular vessels and/or postoperative swelling and inflammation). In a 2012 systematic review, the pooled rate of testicular atrophy following primary orchiopexy was 1.8 percent [86]. Other potential complications include reascent of the testis (requiring repeat procedure), inguinal hernia, infection, and bleeding.

Postoperative management is fairly straightforward. To prevent dislodgement of the testis from the scrotum, straddle toys such as bicycles are avoided for several weeks. Sports activities also are limited in the older child.

Examination one to two weeks postoperatively allows assessment of wound healing and testicular location, although many consider this visit to be optional. The more important examination is performed at least three months postoperatively to assess testicular position and size.

Nonpalpable testes

Imaging — Imaging is not routinely warranted to locate nonpalpable testes. Imaging studies lack the sensitivity and the specificity to alter the need for exploratory surgery [86,89]. (See "Undescended testes (cryptorchidism) in children: Clinical features and evaluation", section on 'Imaging'.)

Exploratory surgery — Exploratory surgery for the nonpalpable testis is diagnostic and potentially therapeutic. The first surgical objective is to determine whether or not the testis is present; viable testes are positioned and fixed within the scrotum; nonviable testicular remnants are removed. At the time of surgery, approximately 10 percent of boys with nonpalpable testes are found to have blind-ending testicular vessels, indicating an absent testicle (picture 4) [90].

Two surgical approaches are used in the management of boys with nonpalpable testes: the open inguinal approach and the laparoscopic approach. The laparoscopic approach usually is undertaken if the surgeon has laparoscopic expertise.

Examination under anesthesia is the first step in the surgical management of the clinically nonpalpable testis [83]. In a series of 263 nonpalpable testes, 18 percent were palpable in the groin during examination under anesthesia, obviating the need for laparoscopy [90]. In addition, if a "nubbin" is palpated in the scrotum, scrotal exploration can confirm the diagnosis of an atrophied testis [91]. Criteria for making a diagnosis of an atrophied testis include identification of a hemosiderin deposit and/or the clear identification of atretic vas deferens and vessels.

Exploration of the groin is the first step in the open inguinal approach [92]. If cord structures or testicular remnants are found, they are removed and the procedure is terminated. Exploration proceeds to the peritoneum if the groin exploration is negative [93].

The diagnostic laparoscopy is a safe procedure in experienced hands [94-96]. The laparoscope, placed via the umbilicus, is used to examine the inguinal rings, determine the patency of the processus vaginalis, and examine the Wolffian structures and testicular vessels. The finding of blind-ending spermatic vessels (picture 4), confirming the absent testis, permits termination of the procedure without a groin incision. Groin exploration is carried out if testicular vessels and vas deferens are visualized exiting the internal ring. The laparoscopic identification of an intra-abdominal testis (picture 1) permits planning for the definitive procedure (eg, open versus laparoscopic).

Associated inguinal hernia — If a patient with undescended testes presents with an incarcerated or strangulated inguinal hernia, expeditious repair at the time of presentation along with orchiopexy should be undertaken. Otherwise, the hernia should be repaired at the time of orchiopexy. (See "Inguinal hernia in children", section on 'Initial management' and 'Orchiopexy' above.)

Hormonal treatment — We do not suggest hormonal treatment for undescended testes. However, historically, some centers have used hormonal treatment in an attempt to induce testicular descent and may continue to use it as an adjunct to surgical treatment to improve fertility [80,97,98]. (See "Undescended testes (cryptorchidism) in children: Clinical features and evaluation", section on 'Pathogenesis'.)

Testicular descent depends upon local concentrations of testosterone considerably greater than can be achieved through systemic administration [99]. However, administration of gonadotropins (either urine-derived human chorionic gonadotropin [hCG] or gonadotropin-releasing hormone [GnRH] analogs) can stimulate the testes to increase production of testosterone sufficiently to achieve the necessary local concentration.

A 2012 systematic review of seven heterogeneous studies (including 995 boys, 1215 testes) of hormonal treatment of cryptorchidism found that [86]:

●Hormonal treatment was associated with modestly higher rates (approximately 10 percent) of testicular descent than placebo. The reported rates of testicular descent in individual studies varied widely (range 9 to 62 percent).

The initial location of the testis may influence the likelihood of success. Greater rates of descent usually are achieved with more distally located testes [100,101]. However, it is possible that some of the distally located testes may have been retractile rather than truly undescended [102-104]. One study suggests that hormonal therapy is effective for retractile testes but not for truly undescended testes [105].

●Information about long-term effects (eg, testicular cancer, fertility) was lacking.

●There was insufficient evidence to suggest the superiority of any particular agent or dosing regimen. GnRH analogs and urine-derived hCG appeared to be similarly effective in achieving testicular descent (range 6 to 35 percent). Only urine-derived hCG is available in the United States.

●Adverse effects are mild and transient, typically resolving within six months of treatment. The most common adverse effects were virilization (eg, hair growth, increase in penis size, erections) and aggressive behavior.

Hormonal treatment is controversial [106,107]. The Nordic consensus on treatment of undescended testes and the 2014 American Urological Association guideline on the evaluation and treatment of cryptorchidism recommend against hormonal treatment [25,83], whereas 2016 European guidelines suggest that hormonal treatment before or after surgical treatment may have a beneficial effect on fertility [80,97].

Long-term follow-up — Boys who have undergone treatment for undescended testes have an increased risk of testicular cancer. We suggest that boys who have undergone treatment for undescended testes be taught how to perform testicular self-examination during adolescence and instructed to perform the examination monthly, in agreement with the recommendations of the American Urologic Association [83]. However, there is a lack of consensus regarding this suggestion. (See "Clinical manifestations, diagnosis, and staging of testicular germ cell tumors", section on 'Testicular examination' and "Screening for testicular cancer".)

MANAGEMENT OF RETRACTILE TESTES — Retractile testes should be examined annually and referred to the urologist for any concerns of ascent to a true undescended position [83,108-110]. Retractile testes are not associated with the same complications as true undescended testes such as increased risk of malignant transformation or subfertility.

In a retrospective review of 204 retractile testes in 122 boys (mean age 5.4 years) who were followed annually for a mean of 2.8 years, approximately one-third became undescended (ascending or acquired undescended), one-third were descended on examination, and one-third remained retractile at the most recent follow-up [111]. Another study suggested that if examination of the contralateral testicle under anesthesia remained abnormal/retractile at the time of a planned unilateral orchidopexy, a bilateral orchiopexy may be warranted because of the risk of developing a metachronous undescended testis [112].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Undescended testes".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or email these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient education" and the keyword[s] of interest.)

●Basics topic (see "Patient education: Undescended testes (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Phenotypically male newborn infants with bilaterally nonpalpable testes, unilaterally nonpalpable testis with hypospadias, or suspected difference of sex development (including congenital adrenal hyperplasia) should be immediately referred to a multidisciplinary team for evaluation and initial management of possible difference of sex development. (See "Evaluation of the infant with atypical genital appearance (difference of sex development)" and "Management of the infant with atypical genital appearance (difference of sex development)".)

●Indications for referral to pediatric urologist or pediatric surgeon may include (see 'Indications for referral' above):

•Congenital palpable or nonpalpable undescended testes (unilateral or bilateral); referral between 4 and 12 months of age is recommended

•Ascending testis in boys beyond infancy (whenever the examination change is noted)

•Palpable tissue in the scrotum that is thought to be an atrophic testis

•Difficulty differentiating between undescended, retractile, or ectopic testis (at any age)

●Most testes that are undescended at birth complete their descent within the first three to four months of life. Spontaneous descent is rare after four months of age. In testes that remain undescended, changes related to fertility may begin to occur before one year of age. (See 'Natural history' above.)

●Complications and sequelae of undescended testes include inguinal hernia, testicular torsion, testicular trauma, subfertility, and testicular cancer. The potential seriousness of these complications and sequelae demands early referral for definitive treatment. (See 'Complications and sequelae' above.)

●The goal of management is to place and fix viable undescended testes in a normal scrotal position or to remove nonviable testicular remnants. Scrotal positioning reduces the risk of torsion and blunt traumatic injury (for intracanalicular testes) and permits easier examination of the testis. If performed sufficiently early, surgical correction also may reduce the risk of infertility and testicular cancer. (See 'Overview' above.)

●Surgical treatment of congenitally undescended testes is recommended as soon as possible after four months of age and definitely should be completed before the child is two years old. In children with testicular ascent later in childhood, surgery generally should be performed within six months of identification. (See 'Timing of surgery' above.)

●Retractile testes should be examined annually and referred for further evaluation if there is concern for ascent. In many cases this will require follow-up until puberty. (See 'Management of retractile testes' above.)