c.AMH.

d.inhibin B.

e.testosterone.

.When in fetal development does the testicle pass into the inguinal canal?

a.5 to 7 weeks’ gestation.

b.10 to 14 weeks’ gestation.

c.20 to 28 weeks’ gestation.

d.30 to 34 weeks’ gestation.

e.None of the above.

.How commonly does cryptorchidism occur in full-term males?

a.Less than 1%

b.1% to 4%

c.5% to 10%

d.15%

e.None of the above

.A 6-month-old full-term male presents with a unilateral nonpalpable testis. The next step after a confirmatory exam is:

a.ultrasound to identify the position of the testis.

b.hormonal therapy.

c.surgical intervention.

d.observation for spontaneous descent until 1 year of age.

e.a and d.

Answers

1.d. SRY. The SRY gene appears to be primarily responsible for male sexual differentiation through complex interactions involving both activation and repression of other male-specific genes.

2.b. Ureter. Androgens (testosterone, dihydrotestosterone) mediate the differentiation of the paired wolffian ducts into the seminal vesicles, epididymis, vas deferens, and ejaculatory ducts.

3.b. Epididymis. Changes in the gubernaculum and processus vaginalis and their innervation by the genitofemoral nerve, as well as hormone secretion by the testis, are all important in the process of testicular descent.

4.d. 15. Testosterone production peaks at 14 to 16 weeks and INSL3 peaks at 15-17 weeks.

5.c. Reactive hydrocele. All of the others are possible complications of

cryptorchidism.

6.b. Cystic fibrosis. All the other syndromes are associated with a higher risk of cryptorchidism; mutations of the cystic fibrosis gene are associated with congenital absence of the vas deferens.

7.d. Vanishing testis syndrome. All the other entities are more frequently associated with cryptorchid testes located in the abdomen.

8.c. Early disappearance of gonocytes. Histological abnormalities that may be present in cryptorchid testes include delayed disappearance of gonocytes, reduced numbers of adult dark (Ad) spermatogonia, reduced number of germ cells per testicular tubule, and carcinoma in situ (CIS).

9.d. 20%. Approximately 20% of undescended testes are nonpalpable at presentation.

.d. Intracanalicular testis, inguinal exploration necessary. Although atretic spermatic vessels seen exiting the internal ring may be associated with a distal vanishing testis, the appearance of the spermatic vessels during laparoscopy is subjective, and therefore exploration (inguinal or laparoscopic) is needed to rule out an intracanalicular viable or atrophic testis. Further exploration is unnecessary if blind-ending intra-abdominal spermatic vessels are found. Hypertrophy of a normally descended contralateral testis is suggestive of monorchism.

.b. It allows for laparoscopic repair of the ipsilateral inguinal hernia when present. An inguinal hernia or patent processus vaginalis does not require formal repair at the time of laparoscopic orchidopexy.

.a. It is less commonly associated with testicular atrophy than laparoscopic orchidopexy. Fowler-Stephens orchidopexy, either 1-or 2-stage, has a higher reported testicular atrophy rate compared with laparoscopic orchidopexy. The other statements are true.

.a. Patent processus vaginalis. Contralateral testicular hypertrophy and a palpable scrotal nubbin may present in boys with unilateral vanishing testis and increase serum FSH and micropenis may be seen in boys with bilateral vanishing testes. The processus vaginalis is closed in most cases of vanishing testis.

.b. Solitary testes in boys with a vanishing testis. In vanishing testis syndrome, the contralateral testis may be larger than expected for age.

.e. Normal anatomy. An abnormal epididymis was reported ipsilateral to 11% to 31% of acquired undescended testes at surgery.

. e. All of the above. All are confounding factors that may affect the reliability

of studies of the efficacy of hormone therapy for cryptorchidism.

.c. a and b. Circumcision should be avoided in the initial management of phenotypic boys with bilateral nonpalpable testes, pending an evaluation for congenital adrenal hyperplasia.

.a. No change in serum testosterone following human chorionic gonadotropin (hCG) stimulation. Serum testosterone may not increase

significantly in response to hCG stimulation in individuals with abnormal testes.

.b. History of prior testicular position provided by the patient’s family.

Testicular position can change with time and/or be difficult to ascertain in

boys with retractile testes; therefore, a careful examination is necessary to differentiate between retractile and undescended testes.

.e. The majority of testes that descend spontaneously do so in the first few months of life. For full-term boys of normal weight, spontaneous testicular descent typically occurs in the first months after birth and is rare after 6 months of age.

.a. 2 to 5 times the risk in normal boys. Surgery may reduce but does not eliminate the risk of TGCT in boys with cryptorchidism, and the risk also exists in the contralateral testis, albeit lower. PLAP + germ cells can be found in normal testes after birth.

.c. Mature teratoma. The risk of benign testicular tumors is not increased in cryptorchidism.

.d. Perianal. All the other answers reflect possible positions for ectopic testes that are possible although rare.

.c. AMH. AMH levels remain high during childhood and are downregulated at puberty.

.a. 20 to 28 weeks’ gestation. The testis passes into the inguinal canal at 20 to 28 weeks’ gestation during the fifth phase of testicular descent.

.b. 1% to 4%. Cryptorchidism is one of the most common congenital anomalies, occurring in 1% to 4% of full-term male infants.

.c. Surgical intervention. If descent has not occurred by 6 months of age, surgical treatment should be performed. Diagnostic imaging has not been shown to change the need for surgery. Hormonal therapy is no longer supported, given the lack of evidence to support its use.

Chapter review

1. The Leydig cell hormones insulin-like 3 and testosterone are required for

testicular descent.

2.Three fourths of undescended testes are palpable; two thirds are unilateral.

3.The etiology of vanishing testis is most likely due to either in utero torsion or a vascular accident.

4.Confirming that the patient has an absent testis requires identifying a blind-ending spermatic artery.

5.The use of human chorionic gonadotropin for the diagnosis and treatment of undescended testis is not recommended.

6.Laparoscopic identification and mobilization of an abdominal testis is preferred. If the testis can be brought to the opposite internal ring, it can usually be placed in the ipsilateral scrotum.

7.Oligospermia or azoospermia occurs in approximately 75% of patients with bilateral cryptorchidism and in 40% of patients with unilateral cryptorchidism. Paternity in patients with unilateral cryptorchidism is similar to the general population despite the semen abnormalities.

8.Patients with nonsyndromic cryptorchidism have a high incidence of epididymal abnormalities and accompanying inguinal hernias.

9.During fetal development, swelling of the gubernaculum is important to allow for enlargement of the inguinal canal to facilitate testicular passage.

10.Prematurity and low birth weight are risk factors for cryptorchidism; other risk factors include maternal smoking, family history, and maternal exposure to diethylstilbestrol.

11.A karyotype should be obtained if neither gonad is palpable or if there is an undescended testis associated with hypospadias.

12.A two-stage Fowler-Stephens repair is successful approximately 60% of the time.

13.There is a twofold to fivefold increase in the risk of testicular cancer in a cryptorchid testis.

14.Histologic abnormalities that may be present in cryptorchid testes include delayed disappearance of gonocytes, reduced numbers of adult dark (Ad) spermatogonia, reduced number of germ cells per testicular tubule, and carcinoma in situ (CIS).

15.If testicular descent has not occurred by 6 months of age, surgical treatment should be performed.