What are the possible causes of referred pain to the scrotum?

Causes of Referred Pain to the Scrotum

Referred pain to the scrotum can originate from multiple non-scrotal sources including kidney stones, retroperitoneal pathology, abdominal conditions, and musculoskeletal disorders. 1

Primary Scrotal Causes of Pain

While the question specifically asks about referred pain, it's important to differentiate between primary scrotal pathology and referred pain:

Common Primary Scrotal Causes

• Testicular torsion: Presents with acute onset of severe unilateral scrotal pain, often with nausea and vomiting 2
• Epididymitis/epididymo-orchitis: Most common cause of acute scrotal pain in adolescent boys and adults, with gradual onset 3
• Torsion of testicular appendage: Most common etiology in prepubertal boys, sometimes presenting with "blue dot sign" 3
• Other scrotal pathologies: Hydrocele, inflammation of tunica vaginalis, trauma, testicular tumors, epididymal cysts, scrotal abscess 3

Non-Scrotal Causes of Referred Pain to Scrotum

Urological Sources

• Kidney stones/renal colic: Pain can radiate along the ureter and refer to the scrotum via shared nerve pathways 1
• Ureteral pathology: Inflammation or obstruction can cause referred scrotal pain
• Prostatitis: Inflammation of the prostate can refer pain to the scrotum

Retroperitoneal Sources

• Retroperitoneal hemorrhage: Including aneurysm rupture 1
• Retroperitoneal tumors: Primary or metastatic lesions can cause referred pain 1
• Retroperitoneal fibrosis: Can compress nerves that supply the scrotum

Abdominal/Pelvic Sources

• Pancreatitis: Can refer pain to the scrotum 1
• Appendicitis: Particularly retrocecal appendicitis
• Pelvic inflammatory disease: Can cause referred scrotal pain 1
• Abdominal aortic aneurysm: Can present with scrotal pain

Musculoskeletal Sources

• Lower back disorders: Herniated discs or nerve impingement at L1-L2 levels
• Muscle injuries: Particularly of the lower abdominal wall or groin 1
• Hip pathology: Hip joint disorders can refer pain to the scrotum

Neurological Sources

• Nerve entrapment syndromes: Ilioinguinal, genitofemoral, or pudendal neuralgia
• Radiculopathy: Lumbar spine pathology affecting nerve roots
• Post-surgical neuropathic pain: Following inguinal hernia repair or vasectomy

Diagnostic Approach

When scrotal ultrasound findings are normal in a patient with acute scrotal pain, non-scrotal causes should be considered:

1. Expanded imaging: Ultrasound investigation of the abdomen, groin, and thighs is indicated 1
2. Consider CT or MRI: For suspected retroperitoneal or abdominal sources
3. Urinalysis: To evaluate for urinary tract infection or kidney stones

Clinical Pearls

• Referred pain to the scrotum is often unilateral and may be accompanied by normal-appearing scrotal contents on examination
• The pain may be exacerbated by specific movements or positions depending on the source
• Pain that improves with scrotal elevation (positive Prehn sign) suggests inflammatory causes rather than testicular torsion 3
• Chronic scrotal content pain without identifiable cause remains a challenging urological problem 4

When evaluating scrotal pain with normal scrotal ultrasound findings, clinicians should maintain a high index of suspicion for non-scrotal pathology to avoid missing potentially serious conditions.