Cryptorchidism

Overview

Definition

Cryptorchidism is the absence of 1 or both testicles in the scrotum. Cryptorchid testis (“hidden testis”) may be undescended or absent (atrophied).

Epidemiology

• Prevalence at birth about 3% overall: 
  • Full-term infants: 2%–5%  
  • Premature infants: 30% 
• Risk factors:
  • Maternal smoking and alcohol exposure 
  • Fetal exposure to paracetamol/acetaminophen and diethylstilbestrol  
  • Prematurity 
  • Small for gestational age and low birth weight
• Cryptorchidism is usually an isolated condition, but there are related disorders:
  • Disorders of sexual differentiation (DSD) 
  • Congenital adrenal hyperplasia (CAH) 
  • Genetic disorders such as Klinefelter syndrome and Prader-Willi syndrome

Pathophysiology

Pathogenesis overall is not well understood but is affected by hormonal and anatomical embryologic factors.

Normal mechanical descent:

• Intra-abdominal phase: mediated by the hormone descendin
• Inguinal phase (by the 28th week of gestation): mediated by androgen/testosterone 
• Gubernaculum swells and pulls the testis down into the scrotum along the inguinal canal. 

Defective mechanisms in the different phases of descent:

• Alterations in hypothalamic-pituitary-adrenal (HPA) axis, especially testosterone 
• In utero, increased expression of estradiol in the placenta 
• Testicular agenesis (from vascular compromise, causing absent testis)
• Changes in abdominal pressure

Clinical Presentation and Diagnosis

Clinical findings

• Palpable: 
  • Suprascrotal (most common location): outside the external inguinal ring 
  • Intracanalicular: inguinal canal 
• Non-palpable:
  • Intra-abdominal 
  • Absent testis 
  • Empty or hypoplastic scrotum

Examination

• Diagnosis is mainly based on a comprehensive physical examination.
  • Testicular exam:
    • Position infant in the supine position.
    • Exam requires warm lubricated hands: 1 hand near the anterior superior iliac spine (ASIS) and the other on the scrotum
    • Use fingertips to sweep from ASIS along the inguinal canal.
  • Genital exam:
    • Assess position of urethral meatus to rule out hypospadias.
    • Check phallus for size and atypical appearance. 
    • Look for hypoplastic scrotum or poorly rugated scrotal skin. 
  • Inguinal exam: Assess for fullness; may indicate hernia or lymphadenopathy.
• Imaging:
  • Generally not necessary as it lacks sensitivity or specificity on treatment decision
  • Ultrasound: may be indicated when ruling out disorder of sexual differentiation or gonads/uterus 

Management

Treatment principles

• Goal: Fix the viable undescended testis in the normal scrotal position or remove nonviable testicular elements.
• Timing: 
  • No spontaneous descent by 6 months of age triggers the need for intervention.
  • Surgery before 2 years of age (ideally before 1 year) 
• Treatment is recommended to:
  • Allow testicular growth and for fertility preservation
  • Reduce the risk of testicular cancer
  • Allow for detection of testicular masses
  • Decrease the risk of testicular torsion

Surgery for palpable testis

• Orchiopexy via inguinal approach: Testis and spermatic cord are released from attachments and the testis is sutured in the scrotum. 
• Complications: testicular atrophy, infection, bleeding, inguinal hernia

Surgery for nonpalpable testis

• Diagnostic laparoscopy to search for intra-abdominal testis
• If no testis is found, must determine presence of blind-ending vessels or testicular nubbin.
• If testis is found, can proceed with laparoscopic orchiopexy (options):
  • Single-stage orchiopexy without division of gonadal vessels 
  • 1-stage Fowler-Stephens (FS) orchiopexy with gonadal vessels divided
  • 2-stage FS orchiopexy where the gonadal vessels are clipped to allow collateral blood flow to testis in 6 months to mobilize testis

Clinical Relevance

• Testicular cancer: Patients with a history of cryptorchidism have an increased risk of testicular cancer (relative risk of 2.9). The most common presentation is a painless testicular nodule. Most of the testicular cancers are germ cell tumors. Diagnosis involves physical exam, testicular ultrasound, serum tumor markers, and metastatic workup. Treatment is radical orchiectomy.  
• Testicular torsion: the most common cause of acute testicular and scrotal emergency pain. Patients have unilateral testicular pain, most frequently caused by a high abnormal attachment of the tunica vaginalis, making it prone to twisting. Scrotal ultrasound is helpful, but testicular torsion is mostly a clinical diagnosis and requires immediate scrotal exploration and orchiopexy. 
• Inguinal canal and hernias: hernia occurs in parts of the abdominal wall where the musculature is not continuous. The increased pressure in the abdominal cavity leads to an evagination (protrusion) of the parietal peritoneum and parts of organs through the surrounding muscles (in this case, the inguinal canal). Diagnosis is made by physical exam and ultrasound, with manual reduction or hernia repair as necessary. 
• Infertility: A history of cryptorchidism will increase the incidence of impaired spermatogenesis and lower fertility rates. Studies show that early orchiopexy and diagnosis of undescended testis will lead to increased fertility preservation. 
• Retractile testis: when the testicles are palpable but in an extra-scrotal position on examination and can be manipulated into the scrotum. The testicles will remain in a dependent scrotal location temporarily and re-ascend. Treatment is with serial exams and monitoring of descent.