Undescended Testes (Cryptorchidism) (Child)

1. Overview

Undescended testis (UDT), or cryptorchidism, is the most common congenital anomaly of the male genitourinary system, affecting approximately 1-5% of full-term male neonates and up to 30% of preterm infants. [1,2] It is defined as the failure of one or both testes to descend from their intra-abdominal position during fetal development to their normal scrotal location by birth or within the first few months of life.

The condition is clinically significant due to its association with impaired fertility, increased risk of testicular malignancy (particularly germ cell tumours), higher incidence of testicular torsion, and psychological impact related to body image. [3,4] Current international guidelines recommend surgical correction (orchidopexy) between 6-12 months of age to optimize fertility potential and facilitate long-term testicular surveillance. [5,6]

Cryptorchidism may be congenital (present at birth) or acquired (ascent of a previously descended testis), with distinct etiological and management considerations. Understanding the embryological basis of testicular descent, accurate clinical differentiation from retractile testes, and timely surgical intervention are fundamental to optimizing long-term outcomes.

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2. Epidemiology

Incidence and Prevalence

The prevalence of cryptorchidism at birth has remained relatively stable over recent decades, though some studies suggest a slight increase in certain geographical regions. [1,7] Approximately 70-80% of cases are unilateral, with the right testis more commonly affected than the left (60% vs 40%). Bilateral cryptorchidism occurs in 10-30% of cases. [2]

Risk Factors

Established Risk Factors:

• Prematurity and low birth weight: Strong inverse correlation with gestational age [8]
• Intrauterine growth restriction (IUGR)
• Family history: 4-fold increased risk with affected first-degree relative [9]
• Maternal factors: Diabetes mellitus, obesity, smoking, alcohol consumption
• Endocrine disruptors: Prenatal exposure to pesticides, phthalates
• Genetic syndromes: Prader-Willi, Klinefelter, Noonan syndrome
• Hormonal abnormalities: Maternal estrogen exposure, low testosterone states

Associated Anomalies:

• Patent processus vaginalis (inguinal hernia): Present in 80-90% of cases [10]
• Hypospadias: Co-occurrence suggests disorders of sexual development
• Abdominal wall defects (prune belly syndrome, gastroschisis)
• Müllerian abnormalities in DSD

Geographical and Temporal Trends

Studies from Nordic countries and the UK suggest regional variations in incidence, potentially related to environmental endocrine disruptor exposure. [7] Temporal trends show relatively stable rates over the past 30 years in most developed nations.

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3. Aetiology and Pathophysiology

Normal Testicular Descent

Testicular descent is a complex biphasic process occurring during fetal development:

Phase 1: Transabdominal Phase (8-15 weeks gestation)

• Controlled primarily by insulin-like peptide 3 (INSL3) secreted by Leydig cells
• INSL3 binds to RXFP2 receptors on the gubernaculum
• Gubernaculum enlargement anchors the testis at the internal inguinal ring
• Regression of the cranial suspensory ligament allows caudal migration
• Androgens play a minor role in this phase

Phase 2: Inguinoscrotal Phase (25-35 weeks gestation)

• Heavily androgen-dependent (testosterone and DHT)
• Gubernaculum-mediated migration through the inguinal canal
• Genitofemoral nerve releases calcitonin gene-related peptide (CGRP)
• Testis enters scrotum by 28-35 weeks
• Processus vaginalis normally obliterates after descent

Postnatal "Mini-Puberty"

During the first 3-6 months of life, there is a physiological surge in gonadotropins (LH/FSH) and testosterone, known as "mini-puberty." [11] This hormonal surge promotes:

• Spontaneous testicular descent in 50-70% of congenital UDT cases
• Sertoli cell maturation and proliferation
• Early germ cell development (transformation of gonocytes to spermatogonia)

Critical Window: If testes have not descended by 6 months of age, spontaneous descent is highly unlikely, as the mini-puberty hormonal surge wanes.

Molecular Pathophysiology

The pathophysiology of cryptorchidism is multifactorial:

Hormonal Deficiencies:

• INSL3/RXFP2 pathway dysfunction: Mutations rare but critical in transabdominal phase
• Androgen insufficiency: Hypogonadotropic or hypergonadotropic hypogonadism
• Abnormal gubernaculum development: Failure of INSL3-mediated gubernaculum swelling
• Impaired genitofemoral nerve function: Reduced CGRP secretion

Mechanical Factors:

• Anatomical obstruction (e.g., abnormal processus vaginalis)
• Short spermatic vessels limiting descent
• Intra-abdominal pressure abnormalities
• Abdominal wall defects preventing normal migration

Genetic Factors:

• Familial clustering suggests genetic component (heritability ~40%)
• Candidate genes: INSL3, RXFP2, HOXA10, GREAT, ESR1, ESR2
• Polygenic inheritance pattern in most cases

Environmental Factors:

• Endocrine-disrupting chemicals (EDCs): Phthalates, bisphenol A, pesticides
• Maternal smoking: 1.5-2-fold increased risk [12]
• Prenatal analgesic exposure (paracetamol, NSAIDs)

Histopathological Changes in Undescended Testes

Early Changes (6-12 months):

• Delayed transformation of gonocytes to Ad spermatogonia
• Reduced Sertoli cell count and maturation
• Germ cell apoptosis begins

Progressive Changes (> 12-18 months):

• Progressive germ cell loss
• Seminiferous tubule atrophy and fibrosis
• Leydig cell hyperplasia (compensatory)
• Basement membrane thickening
• Interstitial fibrosis

Irreversible Damage:

• Time-dependent: Damage accelerates after 12-18 months [13]
• Temperature-dependent: Scrotal temperature is 2-4°C cooler than abdominal
• Bilateral UDT: Both testes may show histological abnormalities even if one is descended

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4. Classification

By Location

Ectopic Locations:

• Superficial inguinal pouch (most common ectopic site)
• Femoral triangle
• Perineal
• Contralateral scrotal (rare)

Clinical Classification

1. Palpable (70-80% of cases)

• Can be manually detected in groin or upper scrotum
• Includes inguinal, high scrotal, and some ectopic testes
• Generally better prognosis

2. Impalpable (20-30% of cases)

• Not detectable on physical examination
• May be intra-abdominal, absent, or in inguinal canal (missed on exam)
• Requires surgical exploration or advanced imaging

3. Retractile (Not True Cryptorchidism)

• Normal testis with exaggerated cremasteric reflex
• Can be manually brought to base of scrotum without tension
• Remains in scrotum without traction for short period
• No surgical intervention required, but follow-up needed (risk of ascending)

Congenital vs. Acquired

Congenital Cryptorchidism:

• Present from birth
• Failure of normal embryological descent
• Accounts for 70-80% of cases

Acquired (Ascending) Cryptorchidism:

• Previously descended testis ascends out of scrotum
• Usually occurs between ages 1-10 years
• Associated with short spermatic cord, patent processus vaginalis
• May represent 20-30% of cases presenting after infancy [14]

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5. Clinical Presentation

Signs and Symptoms

Primary Finding:

• Empty hemiscrotum: Unilateral or bilateral absence of testis in scrotum
• Hypoplastic scrotum: Underdeveloped, smaller scrotal sac (especially bilateral UDT)
• Asymmetric scrotum: Unilateral cases show visible asymmetry

Associated Findings:

• Palpable mass in inguinal region (inguinal UDT)
• Inguinal bulge suggesting hernia
• Abdominal mass (rare, large intra-abdominal testis)

Symptomatic Presentations:

• Most cases are asymptomatic and detected on routine examination
• Pain: Suggests torsion, trauma, or incarcerated hernia
• Acute scrotum: UDT at higher risk for torsion (10-fold increased risk) [15]

Age at Presentation

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6. Clinical Examination

Examination Technique

Accurate examination is critical to differentiate true UDT from retractile testis and to locate the testis.

Optimal Examination Conditions:

1. Warm environment: Cold temperature stimulates cremasteric reflex
2. Warm hands: Essential to avoid reflex retraction
3. Relaxed patient: Infant/child calm, not crying
4. Multiple positions: Supine, frog-leg, cross-legged (tailor position), standing (older children)

Systematic Approach:

Step 1: Visual Inspection

• Assess scrotal size and symmetry
• Look for inguinal fullness or bulge
• Check for associated anomalies (hypospadias, micropenis)

Step 2: Bimanual Palpation

• Start at anterior superior iliac spine (ASIS)
• Sweep hand medially and caudally along inguinal canal toward scrotum
• "Milk down" technique: Use thumb and fingers to gently push testis toward scrotum
• Opposite hand palpates scrotum to capture testis as it descends

Step 3: Assessment

• Is the testis palpable? (Yes → likely inguinal/high scrotal; No → impalpable)
• Can it be manipulated into scrotum? (Yes → assess next step; No → true UDT)
• Does it reach the base of scrotum without tension? (Yes → possibly retractile; No → UDT)
• Does it remain in scrotum after release? (Yes → retractile; No → UDT)

Key Differentiation: Retractile vs. Undescended

Special Examination Techniques

Soap Technique:

• Lubricate hands and groin with soap/lubricant
• Reduces friction, facilitates testis manipulation
• Useful in obese children

Increased Abdominal Pressure:

• Valsalva maneuver in older children
• Crying in infants
• May make inguinal testis more apparent

Bilateral Impalpable Testes: Red Flag

Immediate Considerations:

• Disorders of Sexual Development (DSD): Virilized genetic female (46,XX DSD)
• Congenital Adrenal Hyperplasia (CAH): Salt-wasting crisis risk in newborn period
• Urgent investigations: Karyotype, 17-hydroxyprogesterone, electrolytes, pelvic ultrasound
• Endocrine referral: Paediatric endocrinology consultation within 24-48 hours

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7. Investigations

General Principle

Clinical examination is the primary diagnostic modality. Imaging and laboratory tests are adjuncts, not substitutes for careful physical examination.

Imaging

Ultrasound (US)

• Role: Limited utility in UDT management
• Sensitivity: 45-78% for inguinal testes, less than 10% for intra-abdominal testes
• Specificity: Variable, high false-positive rate
• Indications:
  • NOT routinely recommended for palpable testes [5,6]
  • May be considered in bilateral impalpable testes to assess for intra-abdominal structures
  • Helpful in obese children where examination is difficult
• Limitations: Cannot reliably rule out intra-abdominal testis; poor at predicting testicular viability

Magnetic Resonance Imaging (MRI)

• Higher sensitivity than US for intra-abdominal testes (80-90%)
• Not routinely indicated: High cost, requires sedation in young children
• Potential role: Research settings, complex cases with DSD

Computed Tomography (CT)

• Not recommended: Radiation exposure, no significant advantage over MRI

Laparoscopy

• Gold standard for impalpable testes [16]
• Diagnostic and therapeutic: Can locate, assess viability, and perform orchidopexy or orchiectomy
• Findings:
  • "Intra-abdominal testis: Staged Fowler-Stephens orchidopexy"
  • "Blind-ending vessels: Confirms vanishing testis syndrome (anorchia)"
  • "Testis entering internal ring: Inguinal exploration"
  • "Viable intra-abdominal testis: Immediate or staged orchidopexy"

Laboratory Investigations

Routine Cases (Unilateral Palpable UDT):

• No routine blood tests needed

Bilateral Impalpable Testes:

• Karyotype: Differentiate 46,XY from 46,XX (DSD screening)
• Serum 17-hydroxyprogesterone: Rule out congenital adrenal hyperplasia (CAH)
• Serum electrolytes: Assess for salt-wasting (if CAH suspected)
• LH, FSH, testosterone: Evaluate hypothalamic-pituitary-gonadal axis
• Anti-Müllerian hormone (AMH): Marker of Sertoli cell function (testicular tissue present)
• Inhibin B: Marker of Sertoli cell reserve
• hCG stimulation test (historical): Assess testicular tissue presence
  • Administer hCG, measure testosterone response
  • Rise in testosterone suggests viable testicular tissue
  • Rarely used now; AMH and inhibin B more practical

Pelvic Ultrasound (Bilateral impalpable):

• Identify Müllerian structures (uterus, fallopian tubes) suggesting DSD

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8. Management

General Principles

Goals of Treatment:

1. Optimize fertility potential: Early orchidopexy preserves germ cells [13]
2. Facilitate malignancy surveillance: Scrotal testis easier to examine
3. Reduce torsion risk: Although orchidopexy does not eliminate risk entirely
4. Improve psychological well-being: Normal scrotal appearance
5. Treat associated hernia: Repair patent processus vaginalis

Timing of Intervention:

• International consensus: Orchidopexy between 6-12 months of age [5,6]
• Optimal window: Before 18 months to minimize germ cell loss
• Rationale: Balance spontaneous descent potential (first 3-6 months) vs. irreversible histological damage (after 12-18 months)

Conservative Management (0-6 Months)

Watchful Waiting:

• Congenital UDT in neonates: Observe for spontaneous descent until 3-6 months
• Preterm infants: Higher rate of spontaneous descent; reassess at term-equivalent age
• Criteria for observation:
  • Diagnosis made before 6 months of age
  • Otherwise healthy child
  • No associated DSD concerns
  • Parents counseled on importance of follow-up

Hormonal Therapy:

• hCG (human chorionic gonadotropin) or GnRH (gonadotropin-releasing hormone) historically used
• Current evidence: Low efficacy (15-20% descent rate), temporary effect, not recommended by major guidelines [5,6]
• Potential harms: Penile growth, pubic hair, behavioral changes
• Role in modern practice: Not indicated

Surgical Management

1. Orchidopexy

Indications:

• All cases of true UDT where testis is viable
• Optimal timing: 6-12 months of age

Technique: Inguinal Orchidopexy (Palpable Testis)

Preoperative:

• General anesthesia with caudal or ilioinguinal nerve block
• Prophylactic antibiotics (single dose)

Operative Steps:

1. Incision: Small transverse inguinal incision over internal ring
2. Exposure: Identify and open external oblique aponeurosis
3. Mobilization:
   • Identify spermatic cord structures (vas deferens, testicular vessels)
   • Separate patent processus vaginalis (present in 80-90%) from cord
   • Ligate and divide hernia sac (high ligation)
   • Mobilize testis and cord to achieve tension-free scrotal placement
4. Cremasteric muscle division: Increase cord length
5. Scrotal placement:
   • Create dartos pouch in scrotum via separate scrotal incision
   • Pass testis through subcutaneous tunnel to scrotum
   • Secure testis in dartos pouch (3-point fixation) without tension
6. Closure: Close inguinal and scrotal incisions in layers

Success Rate: > 95% for palpable testes

Technique: Laparoscopic Orchidopexy (Impalpable Testis)

Laparoscopic Assessment:

• Diagnostic laparoscopy via umbilical port
• Systematic inspection of inguinal rings and pelvis
• Findings and management:
  • "Viable intra-abdominal testis near internal ring: Single-stage laparoscopic or open orchidopexy"
  • "High intra-abdominal testis (> 2cm from internal ring): Staged Fowler-Stephens orchidopexy"
  • "Blind-ending vessels above internal ring: Confirms vanishing testis; no further surgery"
  • "Testis at/entering internal ring: Convert to inguinal exploration"

Fowler-Stephens Orchidopexy:

• Indication: High intra-abdominal testis with short vessels
• Principle: Divide testicular vessels, rely on collateral blood supply (vasal and cremasteric arteries)
• Two-Stage Procedure:
  • "Stage 1 (6-12 months): Clip/divide testicular vessels laparoscopically to promote collateral development"
  • "Stage 2 (6 months later): Mobilize testis on vas deferens pedicle, bring to scrotum"
• Success rate: 70-85% (higher atrophy risk than standard orchidopexy)

Single-Stage Orchidopexy:

• Suitable for low intra-abdominal or inguinal testis
• Higher success, lower atrophy risk

2. Orchiectomy

Indications:

• Post-pubertal diagnosis with atrophic, non-functional testis
• Intra-abdominal testis not amenable to orchidopexy (very high, poor collaterals)
• Dysgenetic testis in DSD: Increased malignancy risk
• Vanishing/nubbinous testis: Remnant tissue with no function

Controversies:

• Historical practice favored orchiectomy post-puberty
• Modern view: Consider orchidopexy even in adolescents/adults for psychological benefit and residual function
• Contralateral testis compensation: Can maintain normal testosterone in unilateral UDT

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9. Complications and Long-Term Outcomes

Fertility

Impact of Cryptorchidism on Fertility:

• Semen analysis: Bilateral UDT associated with reduced sperm count, motility, and morphology even after orchidopexy [17]
• Timing critical: Surgery before 12-18 months optimizes germ cell preservation [13]
• Assisted reproduction: Men with bilateral UDT may require IVF/ICSI

Mechanisms of Infertility:

• Germ cell loss due to elevated temperature
• Autoimmune response against abnormal spermatogenesis
• Endocrine dysfunction (partial androgen insensitivity)
• Bilateral involvement affecting both testes

Testicular Malignancy

Relative Risk:

• 5-10-fold increased risk of testicular germ cell tumours (TGCT) compared to general population [3,4]
• Absolute risk: 0.5-1% lifetime risk (vs. 0.1% in general population)
• Tumour type: Seminoma most common, followed by mixed germ cell tumours
• Timing: Peak incidence in young adults (20-40 years)

Risk Factors for Malignancy:

• Bilateral UDT: Higher risk than unilateral
• Intra-abdominal location: Highest malignancy risk
• Late orchidopexy: Risk not significantly reduced by surgery, but facilitates surveillance
• Contralateral testis: Also at increased risk (35-50% of tumours occur in descended testis)

Surveillance:

• Self-examination: Monthly testicular self-exams from puberty
• Clinical examination: Annual follow-up through early adulthood
• Ultrasound: Not routine; use if clinical suspicion or high-risk features
• Tumor markers: β-hCG, AFP, LDH if mass detected

Orchidopexy and Malignancy:

• Does not eliminate malignancy risk
• Facilitates detection: Scrotal testis easier to examine
• Possible slight benefit: Early orchidopexy (before 10 years) may reduce risk modestly

Testicular Torsion

• 10-fold increased risk in UDT compared to descended testes [15]
• Mechanism: Abnormal fixation, bell-clapper deformity, long mesorchium
• Presentation: Acute scrotal/groin pain, nausea, vomiting
• Diagnosis: Difficult; impalpable testis torsion often missed
• Management: Emergency surgical exploration and detorsion ± orchidopexy/orchiectomy

Inguinal Hernia

• 80-90% of UDT have patent processus vaginalis
• Concurrent repair during orchidopexy: High ligation of hernia sac standard practice
• Risk of incarceration: Low, but higher in UDT than general population

Psychological and Psychosocial Impact

• Body image concerns: Particularly in bilateral UDT with small scrotum
• Anxiety and self-esteem: May affect adolescents and adults
• Sexual function: Generally normal after successful orchidopexy
• Counseling: Important component of long-term care

Surgical Complications

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10. Prognosis

Overall Prognosis:

• Excellent with timely diagnosis and surgical correction
• Fertility: Preserved in most unilateral cases; variable in bilateral
• Malignancy: Increased surveillance needed; early detection key
• Quality of life: Generally normal post-orchidopexy

Prognostic Factors:

Long-Term Follow-Up:

• Annual clinical examination through adolescence
• Semen analysis if fertility concerns arise
• Testicular self-examination education at puberty
• Psychological support as needed

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11. Special Scenarios

Acquired (Ascending) Cryptorchidism

• Definition: Testis that was previously in scrotum ascends to inguinal position
• Incidence: 1-7% of boys with initially descended testes [14]
• Peak age: 2-7 years
• Mechanism: Spermatic cord fails to lengthen proportionately to somatic growth
• Management: Orchidopexy recommended (same fertility/malignancy risks as congenital UDT)

Bilateral Impalpable Testes and DSD

Approach:

1. Urgent endocrine evaluation: Karyotype, hormones (LH, FSH, testosterone, 17-OHP, AMH)
2. Pelvic imaging: Ultrasound to detect Müllerian structures
3. Laparoscopy: If testicular tissue suspected (AMH positive), locate testes
4. Gonadectomy: If dysgenetic gonads in DSD (malignancy risk up to 30%)

Retractile Testes

• Not true cryptorchidism: No surgery needed
• Follow-up: Annual examination until puberty
• Risk: 2-45% may develop acquired UDT [6]
• Criteria for reassurance: Easily manipulable to scrotum base, remains there without tension

Undescended Testis in Prader-Willi Syndrome

• High incidence: 80-90% of males
• Often bilateral
• Management: Standard orchidopexy; consider hormonal evaluation
• Associated: Hypogonadotropic hypogonadism; may require testosterone replacement in adolescence

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12. Evidence and Guidelines

Key International Guidelines

Landmark Studies

1. Timing of Surgery and Fertility:

• Hadziselimovic et al. demonstrated progressive germ cell loss after 12 months, supporting early surgery [13]

2. Malignancy Risk:

• Dieckmann et al. meta-analysis: 5-10-fold increased risk; surgery before age 10 may reduce risk modestly [3]

3. Acquired Cryptorchidism:

• Boehme et al. multicenter study: 20-30% of late orchidopexies represent acquired UDT, not missed congenital cases [14]

4. Laparoscopy for Impalpable Testes:

• Tasian et al.: Diagnostic laparoscopy superior to imaging; 80% diagnostic accuracy [16]

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13. Patient and Family Education

For Parents of Newborns

What is an undescended testicle? During pregnancy, your baby's testicles develop inside the abdomen and normally descend into the scrotum before or shortly after birth. In your child, one or both testicles have not completed this journey.

Will it come down on its own?

• If your baby is under 3 months old, there is a good chance (50-70%) it will descend naturally.
• After 6 months, spontaneous descent is very unlikely.

Why does my child need surgery?

1. Fertility: The scrotum is cooler than the body, which is essential for healthy sperm production in the future.
2. Cancer risk: Although small (about 0.5-1%), a scrotal testis is easier to examine for lumps when he is older.
3. Testicular torsion: Undescended testes can twist on their blood supply, causing pain and damage.

When should surgery be done?

• Best between 6-12 months of age, ideally before 18 months.
• This timing balances waiting for natural descent with preventing long-term damage.

What does the surgery involve?

• Orchidopexy (moving the testis into the scrotum)
• Day-case procedure under general anesthesia
• Small incisions in the groin and scrotum
• Testis fixed in a pouch in the scrotum
• Most children go home the same day

Recovery:

• Mild discomfort for a few days (pain relief with paracetamol/ibuprofen)
• Avoid strenuous activity for 2 weeks
• Follow-up appointment to check healing

Long-term outlook:

• Excellent in most cases
• Normal appearance and function
• Your child will need lifelong awareness of testicular self-examination starting in teenage years

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14. Examination Focus for MRCPCH / Paediatric Surgery Exams

Common Exam Questions

1. Diagnosis and Differentiation

• Q: "Newborn with bilateral impalpable testes. What are your immediate concerns and investigations?"
• Answer: Consider disorders of sexual development (DSD), particularly virilized 46,XX (CAH). Urgent investigations: karyotype, serum 17-hydroxyprogesterone, electrolytes, pelvic ultrasound. Pediatric endocrinology referral within 24-48 hours.

2. Management Timing

• Q: "At what age should orchidopexy be performed and why?"
• Answer: Between 6-12 months of age, ideally before 18 months. Rationale: Allows time for spontaneous descent in first 3-6 months (mini-puberty surge), but intervenes before irreversible germ cell damage occurs (after 12-18 months).

3. Retractile vs. Undescended

• Q: "How do you differentiate retractile testis from true cryptorchidism?"
• Answer: Retractile testis can be manually brought to base of scrotum without tension and remains there for minutes without traction. Undescended testis either cannot reach scrotum base or immediately retracts when released. Retractile testis requires observation, not surgery.

4. Investigations

• Q: "What is the role of ultrasound in undescended testis?"
• Answer: Limited. Not routinely indicated for palpable testes (examination is sufficient). Poor sensitivity for intra-abdominal testes (less than 10%). Diagnostic laparoscopy is gold standard for impalpable testes.

5. Complications

• Q: "What are the long-term risks of untreated cryptorchidism?"
• Answer: Infertility (progressive germ cell loss), 5-10-fold increased testicular malignancy risk (seminoma), 10-fold increased torsion risk, psychological impact, associated inguinal hernia.

6. Surgical Technique

• Q: "Describe the Fowler-Stephens procedure."
• Answer: Two-stage orchidopexy for high intra-abdominal testis. Stage 1: Divide testicular vessels to promote collateral circulation (vasal and cremasteric). Stage 2 (6 months later): Mobilize testis on vas deferens pedicle and bring to scrotum. Success rate 70-85%; higher atrophy risk.

Viva Points

Opening Statement: "Undescended testis, or cryptorchidism, is the most common congenital urogenital anomaly in males, affecting 1-5% of full-term newborns. It is defined by failure of testicular descent from the abdomen to the scrotum by birth or within the first few months of life. Management involves careful examination to differentiate from retractile testis, observation for spontaneous descent in early infancy, and surgical orchidopexy between 6-12 months if the testis remains undescended, to preserve fertility potential and facilitate malignancy surveillance."

Key Facts to Mention:

• Bilateral cryptorchidism (20-30% of cases); unilateral more common (70-80%)
• Spontaneous descent in 50-70% by 3-6 months (postnatal mini-puberty surge)
• Irreversible germ cell damage after 12-18 months; early surgery critical [13]
• Orchidopexy success > 95% for palpable testes
• Laparoscopy gold standard for impalpable testes
• 5-10-fold increased testicular cancer risk persists despite surgery [3,4]
• Bilateral impalpable testes: rule out DSD/CAH urgently

Common Mistakes to Avoid

• ❌ Ordering routine ultrasound for palpable UDT (unnecessary, low yield)
• ❌ Delaying surgery beyond 18 months (irreversible fertility damage)
• ❌ Misdiagnosing retractile testis as UDT (overtreatment)
• ❌ Missing bilateral impalpable testes at birth (DSD/CAH emergency)
• ❌ Recommending hormonal therapy (outdated, ineffective per guidelines)
• ❌ Failing to counsel on lifelong testicular self-examination (malignancy surveillance)

Model Answer Example

Q: "A 9-month-old boy is referred with right undescended testis noted at 6-week check. Outline your management."

A: "I would take a systematic approach to this common paediatric surgical condition.

History:

• Confirm testis location at birth and any changes
• Assess gestational age (prematurity increases risk)
• Family history of cryptorchidism or genetic syndromes
• Associated features: hypospadias, inguinal hernia
• Developmental history

Examination:

• In warm room, with warm hands, relaxed child
• Assess both hemiscrotums
• Bimanual palpation: sweep from ASIS along inguinal canal to scrotum
• Determine if testis is palpable, can reach scrotum, and stays there
• Check for inguinal bulge (hernia), contralateral testis, other anomalies

Investigations:

• None routinely required if palpable and no DSD features
• Karyotype, hormones, pelvic US only if bilateral impalpable or DSD suspected

Management:

• Referral to paediatric surgery/urology for orchidopexy
• Timing: Ideally at 9-12 months of age (within current window)
• Surgical approach:
  • Inguinal orchidopexy if palpable
  • Laparoscopy if impalpable
  • Concurrent hernia repair (high ligation of processus vaginalis)
• Parental counseling: Explain rationale (fertility, malignancy surveillance), surgical procedure, recovery, long-term outlook
• Follow-up: Postoperative check, annual examination, testicular self-exam education at puberty

Long-term:

• Monitor for atrophy, ascent
• Counsel on lifelong testicular cancer surveillance
• Fertility assessment if concerns arise in adulthood"

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15. References

1. Sijstermans K, Hack WW, Meijer RW, van der Voort-Doedens LM. The frequency of undescended testis from birth to adulthood: a review. Int J Androl. 2008;31(1):1-11. doi:10.1111/j.1365-2605.2007.00770.x

2. Hutson JM, Balic A, Nation T, Southwell B. Cryptorchidism. Semin Pediatr Surg. 2010;19(3):215-224. doi:10.1053/j.sempedsurg.2010.04.001

3. Dieckmann KP, Pichlmeier U. Clinical epidemiology of testicular germ cell tumors. World J Urol. 2004;22(1):2-14. doi:10.1007/s00345-004-0398-8

4. Cheng L, Albers P, Berney DM, et al. Testicular cancer. Nat Rev Dis Primers. 2018;4(1):29. doi:10.1038/s41572-018-0029-0

5. Radmayr C, Dogan HS, Hoebeke P, et al. Management of undescended testes: European Association of Urology/European Society for Paediatric Urology Guidelines. J Pediatr Urol. 2016;12(6):335-343. doi:10.1016/j.jpurol.2016.07.014

6. Kolon TF, Herndon CDA, Baker LA, et al. Evaluation and treatment of cryptorchidism: AUA guideline. J Urol. 2014;192(2):337-345. doi:10.1016/j.juro.2014.05.005

7. Virtanen HE, Toppari J. Epidemiology and pathogenesis of cryptorchidism. Hum Reprod Update. 2008;14(1):49-58. doi:10.1093/humupd/dmm027

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