What are the possible causes and treatments for a patient with a swollen right testicle, absent left testicle, and absent cremasteric reflex?

Swollen Right Testicle with Absent Left Testicle and Absent Cremasteric Reflex

This presentation demands immediate surgical exploration for testicular torsion of the right testicle—do not delay for imaging if clinical suspicion is high, as testicular salvage depends critically on intervention within 4-8 hours. 1

Immediate Clinical Assessment

The combination of a swollen right testicle with absent cremasteric reflex is highly suspicious for testicular torsion, which presents with:

• Sudden onset of severe unilateral testicular pain 2
• Swollen scrotum with high-riding testicle 2, 1
• Absent cremasteric reflex (present in 94.9% of torsion cases) 3
• Negative Prehn sign 4, 5
• Associated nausea and vomiting 1

The absent left testicle requires separate evaluation to determine if this represents:

• Previous orchiectomy (obtain surgical history)
• Cryptorchidism (undescended testicle) 6
• Anorchia (congenital absence) 6

Management Algorithm for the Swollen Right Testicle

If Testicular Torsion is Suspected Clinically:

Proceed directly to emergency surgical exploration without imaging. 7, 1 Testicular torsion is a clinical diagnosis, and imaging should never delay surgical intervention when clinical suspicion is high. 1

• Timing is critical: There is a 4-8 hour window before permanent ischemic damage occurs 1
• Testicular salvage rate is 39% when median symptom duration is 90 hours, versus successful preservation when intervention occurs within 12 hours 3
• Delay in treatment results in orchiectomy rates of 42% in boys undergoing surgery for torsion 1

If Clinical Presentation is Equivocal:

Obtain point-of-care Doppler ultrasound immediately (do not send to radiology if this delays care): 7, 2

• Look for decreased or absent blood flow in the affected testicle 2, 3
• Identify the "whirlpool sign" of the spermatic cord (most specific finding) 7, 2
• Assess for heterogeneous hypoechoic echotexture (present in all orchiectomy cases) 4, 3
• Color Doppler showing relative decrease or absence of blood flow confirms torsion 2

However, if ultrasound is not immediately available or shows equivocal findings, proceed to surgical exploration anyway—negative exploration is preferable to testicular loss. 1

Evaluation of the Absent Left Testicle

In Newborns or Infants:

If bilateral nonpalpable testes are present, immediately evaluate for disorder of sexual development and congenital adrenal hyperplasia, as this can be life-threatening with shock, hyponatremia, and hyperkalemia. 6 Do not circumcise until workup is complete. 6

In Children (>6 months) or Adults:

Physical examination is paramount—more than 70% of cryptorchid testes are palpable by an experienced examiner. 6

If the left testicle is truly nonpalpable:

• Do not obtain ultrasound or other imaging prior to urology referral, as these studies have only 45% sensitivity and 78% specificity for localizing nonpalpable testes and rarely assist in decision-making 6
• Refer immediately to urology for surgical exploration (diagnostic laparoscopy or open exploration) to confirm presence or absence of the testis 6

If the patient has a history of cryptorchidism:

• Measure Müllerian inhibiting substance (MIS/AMH), FSH, LH, and testosterone to evaluate for anorchia versus undescended testis 6
• If MIS and inhibin B are undetectable with elevated FSH, this confirms anorchia and surgical exploration is not necessary 6
• If endocrine markers are normal, testicular tissue is present and surgical exploration is mandatory 6

In Adults with Known Unilateral Absence:

Assess hormonal function and fertility status: 8

• If the absent testicle was removed in childhood or represents true anorchia, the remaining right testicle typically provides adequate hormonal function 8
• Men with unilateral cryptorchidism have paternity rates nearly equivalent to men without cryptorchidism 8
• All men with history of cryptorchidism have 3.6-7.4 times higher risk of germ cell tumors and should perform regular testicular self-examinations 8, 9

Critical Pitfalls to Avoid

• Never delay surgical exploration for imaging when testicular torsion is clinically suspected—every hour of delay decreases salvage rates 1
• Never rely on Prehn sign alone to differentiate epididymitis from torsion, as it has poor sensitivity and specificity 7
• Never perform scrotal biopsy or scrotal incision for suspected malignancy—only inguinal orchiectomy is appropriate 7
• Do not obtain ultrasound for cryptorchidism evaluation prior to urology referral, as it is non-contributory with 45% sensitivity 6
• Do not use hormonal therapy to induce testicular descent, as evidence shows low response rates (6-38%) and lack of long-term efficacy 6

Additional Considerations

If the right testicle is salvaged after torsion, bilateral orchiopexy should be performed to prevent future torsion of either testicle. 4, 5

If the absent left testicle represents cryptorchidism and the patient is an adult, orchidectomy should be offered if hormonal function is normal, as the risk of malignancy (2-6% lifetime risk) outweighs preservation benefits. 8 Simultaneous testicular biopsy for intratubular germ cell neoplasia should be performed if orchidopexy is chosen instead. 8

Document the cremasteric reflex status carefully, as its absence is present in 94.9% of testicular torsion cases and is a key clinical finding. 3 However, note that retractile testes are associated with hyperactive cremasteric reflex and increased risk of secondary testicular ascent. 6