Ectopic testis refers to the testis entering a location other than the scrotum after passing the inguinal canal. Ectopic testis usually derives from overdevelopment and lengthening of a segment of the gubernaculum or from obstruction of the entrance to the scrotum 1). The ectopic location of testis is associated with a number of complications such as trauma, torsion and infertility in bilateral cases 2). Ectopic testis diagnosis can easily be made through physical examination of the ectopic regions and an empty scrotum. Imaging techniques such as ultrasonography and tomography may rarely be required. Surgical relocation of the testis into a normal intrascrotal position represents the basis of treatment, and the operation must be performed between the ages of six and 12 months 3).
Undescended testicle also known as cryptorchidism, occurs when one or both testicles fail to move into the scrotum before birth. Cryptorchidism (undescended testicle) is the commonest genital malformation in boys with one-third of premature boys being affected and 2–5% of full-term boys having at least one undescended testicle 4). Overall, 3% of full-term male newborns have undescended testicle (cryptorchidism), decreasing to 1% in male infants aged 6 months to 1 year. The prevalence of undescended testicle is 30% in premature male neonates. Testicles form in the abdomen during fetal development. During the last couple of months of normal fetal development, the testicles gradually descend from the abdomen through a tube-like passageway in the groin (inguinal canal) into the scrotum. With an undescended testicle, that process stops or is delayed. Factors that predispose to cryptorchidism include prematurity, low birth weight, small size for gestational age, twinning, and maternal exposure to estrogen during the first trimester. Seven percent of siblings of boys with undescended testes have cryptorchidism. Spontaneous descent after the first year of life is uncommon.
In the United States, the prevalence of cryptorchidism ranges from 3.7% at birth to 1.1% from age 1 year to adulthood. Internationally, prevalence ranges from 4.3-4.9% at birth to 1-1.5% at age 3 months to 0.8-2.5% at age 9 months 5). Cryptorchidism is identified in 1.5-4% of fathers and 6.2% of brothers of patients with cryptorchidism. Heritability in first-degree male relatives is estimated to be 0.67.
An ectopic testis accounts for about 10% of extrascrotal testes. Perineal ectopic testis is a rare congenital anomaly seen in approximately 1% of all cases of undescended testes 6). Early correction is thought to be able to minimize the risk of infertility, although treatment below the age of 13 does not appear to reduce the risk of malignancy 7). Ectopic testes are misdirected along the course of their remaining descent to arrive at an abnormal position. The most common regions in descending order are superficial inguinal pouch (Denis Browne pouch), perineum, femoral canal, contralateral scrotum and prepenile region 8).
Guidelines published by the American Urological Association in 2014 include the following 9):
- Referral for cryptorchidism should occur by 6 months of age
- Imaging for cryptorchidism is not recommended prior to referral. Do not perform ultrasound (US) or other imaging modalities in the evaluation of boys with cryptorchidism prior to referral, as these studies rarely assist in decision making.
- In prepubertal boys with nonpalpable testes, perform examination under anesthesia to reassess for palpability of testes. If nonpalpable, surgical exploration—and, if indicated, abdominal orchidopexy—should be performed.
- In boys with bilateral, nonpalpable testes who do not have congenital adrenal hyperplasia (CAH), measure Müllerian Inhibiting Substance (MIS or Anti-Müllerian Hormone [AMH]) level), and consider additional hormone testing, to evaluate for anorchia.
- In boys with retractile testes, assess the position of the testes at least annually to monitor for secondary ascent.
- Orchiopexy is the most successful therapy to relocate the testis into the scrotum
- In boys with a normal contralateral testis, consider performing orchiectomy (removal of the undescended testis) if a boy has a normal contralateral testis and either very short testicular vessels and vas deferens, dysmorphic or very hypoplastic testis, or postpubertal age.
- Hormonal therapy is not recommended
- Successful scrotal repositioning of the testis may reduce but does not prevent the potential long-term issues of infertility and testis cancer
- Appropriate counseling and follow-up of the patient are essential
Ectopic testis causes
The cause of ectopic testis is unknown. Extensive research and clinical observations have elucidated some of the factors involved, but the exact mechanism of cryptorchidism has proved elusive.
Birth weight is the principal determining factor for undescended testes at birth to age 1 year, independent of the length of gestation.
One study found that almost 23% of index patients with undescended testes had a positive family history of cryptorchidism, as opposed to 7.5% in control families 10). The familial cluster is 3.6 fold overall, 6.9 if a brother is affected and 4.6 if the father. Mutations in the homeobox gene HOXA10, which plays a pivotal role in regulation of testicular descent, may be involved in select cases 11).
Transabdominal descent of the testis involves differential growth of vertebrae and pelvis until 23 weeks’ gestation. Afterward, further descent is facilitated by the development of the gubernaculum, processus vaginalis, spermatic vessels, and scrotum 12). A normal hypothalamic-pituitary-gonadal axis is a prerequisite for testicular descent 13). Furthermore, testosterone and its conversion to dihydrotestosterone (DHT) are also necessary for continued migration, especially during the inguinoscrotal phase 14).
Exposure to endocrine-disrupting chemicals may contribute to cryptorchidism, and may account for the increasing incidence rate of cryptorchidism seen in some regions. Synthetic chemicals identified as endocrine disruptors include phthalates, pesticides, brominated flame retardants, diethylstilbestrol, and dioxins 15). Different studies have found conflicting data regarding the involvement of müllerian-inhibiting substance, prenatal estrogen exposure, and descendin (a specific gubernacular growth factor) in the pathophysiology of cryptorchidism 16).
Although its exact mechanism of action is unclear, the gubernaculum has significant importance in undescended testes. In patients with cryptorchidism, the gubernaculum is not firmly attached to the scrotum, and the testis is not pulled into the scrotum 17). Both hormonal and mechanical factors appear to mediate the aid of the gubernaculum and descent of the testis 18). The genitofemoral nerve may also aid in descent and gubernacular differentiation, which may be mediated by calcitonin gene-related peptide 19).
Intra-abdominal pressure also appears to play a role in testicular descent. Conditions associated with decreased pressure include prune belly syndrome, cloacal exstrophy, omphalocele, and gastroschisis, among other various syndromes. Each is associated with an increased risk of undescended testes 20). The effect of decreased intra-abdominal pressure is most significant during transinguinal migration to the scrotum, probably in conjunction with androgens and a patent processus vaginalis 21).
Epididymal abnormalities often accompany undescended testes, but the causal relationship has not been established. In 1992, Elder 22) concluded that most epididymal abnormalities probably do not contribute to maldescent.
A Japanese study found that nationwide, the discharge rate of cryptorchidism increased by 14.3% after the Fukushima nuclear accident 23). Rates of other risk factors for cryptorchidism (ie, low-weight babies, preterm births) remained almost constant during the study period, and age distribution of cryptorchidism surgery also did not change 24).
Ectopic testis risk factors
Factors that might increase the risk of an undescended testicle in a newborn include:
- Low birth weight
- Premature birth
- Family history of undescended testicles or other problems of genital development
- Conditions of the fetus that can restrict growth, such as Down syndrome or an abdominal wall defect
- Alcohol use by the mother during pregnancy
- Cigarette smoking by the mother or exposure to secondhand smoke
- Parents’ exposure to some pesticides
Ectopic testis symptoms
Not seeing or feeling a testicle where you would expect it to be in the scrotum is the main sign of an ectopic testis.
Approximately 80% of undescended testes are palpable and 20% are nonpalpable 25). Most intra-abdominal testes are found within a few centimeters of the internal inguinal ring. Absent or vanishing testes are thought to be due to an intrauterine or perinatal vascular event, most likely during late gestation since most of these testicular nubbins are found below the internal inguinal ring. Only 20-40% of nonpalpable testes are absent upon surgical exploration.
Ectopic testes exit the external inguinal ring and are then misdirected along the normal course of the testis. Retractile testes may be palpated anywhere along the natural course of the testis, although most are inguinal. Although not truly undescended, these testes may be suprascrotal secondary to an active cremasteric reflex. This reflex is usually weak in infants and most active in boys aged 5 years. These testes can be manipulated into the scrotum, where they remain without tension. This condition is considered a variant of normal; however, the risk of ascent may approach 50% 26). Ascent probably represents an undescended testis that was almost in normal position. The distinction can be difficult, even to an experienced pediatric urologist. Therefore, children with retractile testes should be monitored regularly, at least until puberty.
Several authors have examined the anatomic position of cryptorchid testes. Cendron and Duckett 27) documented the position upon physical examination and compared this with position at the time of surgery. On physical examination, testicular positions were as follows:
- Nonpalpable – 32.8%
- Above the tubercle – 11.8%
- At the tubercle – 34.7%
- Upper scrotum – 15.3%
- Suspected ectopia – 5.4%
At surgery, testicular findings were as follows:
- Intra-abdominal – 9%
- Peeping testis – 20%
- Tubercle – 42%
- Upper scrotum – 8%
- Superficial inguinal pouch/ectopic – 12%
- Absent or atrophic – 9%
Associated anomalies and conditions may include the following:
- Patent processus vaginalis
- Abnormal epididymis
- Cerebral palsy
- Mental retardation
- Wilms tumor
- Abdominal wall defects (eg, gastroschisis, omphalocele, prune belly syndrome)
In general, ductal abnormalities, hernias (patent processus vaginalis), and testicular maldevelopment are more common in patients with abdominal testes. Overall, 32-79% of undescended testes are associated with some type of epididymal abnormality. However, abnormalities that inhibit sperm transport (eg, complete caput separation, atresia, agenesis) have been reported in only 8% of patients with cryptorchidism. In addition, when the processus vaginalis is patent, the epididymis is more likely to be abnormal.
Ectopic testis complications
In order for testicles to develop and function normally, they need to be slightly cooler than normal body temperature. The scrotum provides this cooler environment. Complications of a testicle not being located where it is supposed to be include:
- Testicular cancer. Testicular cancer usually begins in the cells in the testicle that produce immature sperm. What causes these cells to develop into cancer is unknown. Men who’ve had an undescended testicle have an increased risk of testicular cancer. The risk is greater for undescended testicles located in the abdomen than in the groin, and when both testicles are affected. Surgically correcting an undescended testicle might decrease, but not eliminate, the risk of future testicular cancer.
- Fertility problems. Low sperm counts, poor sperm quality and decreased fertility are more likely to occur among men who’ve had an undescended testicle. This can be due to abnormal development of the testicle, and might get worse if the condition goes untreated for an extended period of time.
Other complications related to the abnormal location of the undescended testicle include:
- Testicular torsion. Testicular torsion is the twisting of the spermatic cord, which contains blood vessels, nerves and the tube that carries semen from the testicle to the penis. This painful condition cuts off blood to the testicle. If not treated promptly, this might result in the loss of the testicle. Testicular torsion occurs 10 times more often in undescended testicles than in normal testicles.
- Trauma. If a testicle is located in the groin, it might be damaged from pressure against the pubic bone.
- Inguinal hernia. If the opening between the abdomen and the inguinal canal is too loose, a portion of the intestines can push into the groin.
Ectopic testis diagnosis
If your son has a ectopic testis or undescended testicle, his doctor might recommend surgery for diagnosis and potential treatment:
- Laparoscopy. A small tube containing a camera is inserted through a small incision in your son’s abdomen. Laparoscopy is done to locate an intra-abdominal testicle. The doctor might be able to fix the undescended testicle during the same procedure, but an additional surgery might be needed in some cases. Alternatively, laparoscopy might show no testicle present, or a small remnant of nonfunctioning testicular tissue that is then removed.
- Open surgery. Direct exploration of the abdomen or groin through a larger incision might be necessary in some cases.
After birth, if the doctor can’t detect any testicles in the scrotum, he or she might order further testing to determine if the testicles aren’t there at all rather than undescended. Some conditions that result in absent testicles can cause serious medical problems soon after birth if left undiagnosed and untreated.
Imaging tests, such as an ultrasound and MRI, generally aren’t recommended for diagnosing an undescended testicle.
Ectopic testis treatment
Treatment for ectopic testis is surgical and should not be delayed, as there is no need to await a possible descent 28). The goal of treatment is to move the ectopic testis to its proper location in the scrotum. Treatment before 1 year of age might lower the risk of complications of an undescended testicle, such as infertility and testicular cancer. Earlier is better, but it’s recommended that surgery takes place before the child is 18 months old. As per guidelines from British Association of Paediatric Urologist 29), surgery should take place between 3 and 6 months and definitely before 1 year. This procedure can be done either with a laparoscope or with open surgery (orchidopexy). The surgeon carefully manipulates the testicle into the scrotum and stitches it into place (orchiopexy).
Orchiopexy, the most common surgical procedure for correcting a single descending testicle, has a success rate of nearly 100 percent. Fertility for males after surgery with a single undescended testicle is nearly normal, but falls to 65 percent in men with two undescended testicles. Surgery might reduce the risk of testicular cancer, but does not eliminate it.
Ectopic testis surgery
Ectopic testis surgery is done while the child is asleep (unconscious) and pain-free under general anesthesia. The surgeon makes a cut in the groin. This is where most undescended testes are located.
After finding the cord that holds the testis in the scrotum, the surgeon unties it from the tissue around it. This allows the cord to extend to its full length. A small cut is made in the scrotum, and a pouch is created. The testicle is pulled down into the scrotum, and stitched into place. Stitches are used to close the surgical cuts.
In some cases, the procedure can be done laparoscopically. This involves smaller surgical cuts.
When the testicle is located very high, correction may require two stages. Separate surgeries are done several months apart.
In some cases, the testicle might be poorly developed, abnormal or dead tissue. The surgeon will remove this testicular tissue.
If your son also has an inguinal hernia associated with the undescended testicle, the hernia is repaired during the surgery.
Ectopic testis surgery is successful in most cases. A small percentage of men will have fertility problems.
Men who have had undescended testicles should do monthly self-exams for the rest of their lives to look for possible tumors. Men with undescended testes have higher rates of testicular cancer than those with normal testicle development, even if they have a fully descended testicle on the other side. There is also a higher risk for testicular cancer in the other testicle that descended normally. Bringing the testicles down will make it easier to monitor for tumor growth in the future.
Ectopic testis surgery risks
Risks for any anesthesia are:
- Reactions to medicines
- Problems breathing
Risks for any surgery are:
Complications of ectopic testis surgery are as follows:
- Inability to bring the testicle into the scrotum, resulting in the removal of the testicle. Inadequate testis position occurs in up to 10% of patients and is due to incomplete retroperitoneal dissection. It is usually corrected with a second procedure.
- Shrinkage of the testicle or failure of the testicle to grow to normal size. Testicular atrophy due to devascularization during dissection of the cord occurs in approximately 5% of patients. Orchiectomy may be indicated to treat cancer, with subsequent prosthesis placement if requested.
- Accidental division of the vas deferens occurs in 1-2% of patients. Immediate or postpubertal microvascular repair may be used.
- Epididymoorchitis is uncommon and may be treated with antibiotics.
- Scrotal swelling may occur and is usually secondary to edema. If progressive, it may be due to bleeding and should be explored. A later presentation of swelling may be secondary to a hydrocele, which, if large, requires transscrotal repair.
Complications of laparoscopy include the following:
- Preperitoneal emphysema may develop secondary to poor needle or trocar placement and insufflation.
- Hypercarbia may occur with pneumoperitoneum. This can be counteracted by increasing minute ventilation and keeping insufflation pressures at less than 12 mm Hg.
- The puncture of a viscus with the Veress needle is not harmful unless insufflated or dilated by a trocar.
- The puncture of a major abdominal vessel is a life-threatening complication. The needle or sheath should be left in place for tamponade, and an emergency open laparotomy is performed. (Almost all the above potentially life-threatening vascular and enteric complications can be avoided by using an open technique for access.)
- Injury to the inferior epigastric vessels may also occur with trocar placement. Hemostasis can be achieved via direct cautery or via suture/clip ligation from the external surface or laparoscopically.
- Bladder puncture may occur because the bladder is intra-abdominal in younger children. Care must be taken when placing lower abdominal and scrotal trocars. Repair can be achieved laparoscopically or through a small suprapubic incision. A ureteral injury requires stenting.
Follow-up and monitoring
After surgery, the surgeon will monitor the testicle to see that it continues to develop, function properly and stay in place. Monitoring might include:
- Physical exams
- Ultrasound exams of the scrotum
- Tests of hormone levels
Even after corrective surgery, it’s important to check the condition of the testicles to ensure they develop normally. Check the position of his testicles regularly during diaper changes and baths.
Self-examination of testicles will be an important skill for early detection of possible tumors.
If your son doesn’t have one or both testicles — because one or both are missing or didn’t survive after surgery — you might consider saline testicular prostheses for the scrotum that can be implanted during late childhood or adolescence. These prostheses give the scrotum a normal appearance.
If your son doesn’t have at least one healthy testicle, your child’s doctor will refer him to a hormone specialist (endocrinologist) to discuss future hormone treatments that would be necessary to bring about puberty and physical maturity.
If your son doesn’t have one or both testicles, he might be sensitive about his appearance. He might have anxieties about looking different from friends or classmates, especially if he has to undress in front of others in a locker room. The following strategies might help him cope:
- Teach your son the right words to use when talking about the scrotum and testicles.
- Explain that there are usually two testicles in the scrotum. If he’s missing one or both, explain what that means and that he’s still a healthy boy.
- Remind him that he’s not ill or in danger of illness.
- Talk to him about whether a testicular prosthesis is a good option for him.
- Help him practice a response if he’s teased or asked about the condition.
- Buy him loosefitting boxer shorts and swim trunks that might make the condition less noticeable when changing clothes and playing sports.
- Be aware of signs of worry or embarrassment, such as not participating in sports that he’d normally enjoy.
References [ + ]
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