What is the Differential Diagnosis of Scrotal Swelling?

Patient Presentation
A term male infant was born by vaginal delivery without complications. During his physical examination it was noted that his left scrotum appeared swollen.
The scrotum transilluminated light, but no testicle could be palpated. The right testicle and scrotum were normal as was the rest of his examination.
The patient’s clinical course over the next day showed an slightly fussy infant with a bluish hue to the left scrotum, but no other changes in his examination.
Urology was consulted and an ultrasound was ordered to rule out testicular torsion. The diagnosis of left hydrocele with no testicular torsion and normal vascular flow was made. He will followup with his regular physician and
return to urology if it does not improve in 6 months.

Figure 38 – Longitudinal color and pulse-wave doppler ultrasound images of the right and left testicles reveal normal arterial blood flow to each testicle, which rules out testicular torsion. A very small right hydrocoele and a very large left hydrocele are also seen.

Hydroceles are one of the most common causes of painless scrotal swelling. It is caused by fluid accumulations in the tunica vaginalis due to incomplete obliteration of the processes vaginalis with the peritoneal cavity. They are very common in preterm and term infants. Generally they do not cause problems but if the processes vaginalis does not close a hernia may occur.

Testicular torsion is a common cause of acute painful scrotal swelling. If there is inadequate fixation of the testis to the scrotal sac then the testis may rotate (often medially) causing torsion of the spermatic cord with constriction of the vascular supply and subsequent arterial infarction.
The patients present with sudden onset of pain in the scrotum that may radiate to the abdomen. Nausea and vomiting may occur. The testis often is higher in the scrotal sac than the contralateral testis and there is diffuse testicular and scrotal pain and edema. Erythema or ecchymosis may occur. An absent cremasteric reflex suggests the diagnosis.
After just a few hours of pain the testis may not be viable.
Patients may have cycles of torsion and detorsion and thus present with waxing and waning symptoms. Waning pain may also indicate that the testis has already infarcted.

Urological consultation and scrotal ultrasound with doppler imaging should be performed emergently if suspected. Absent arterial flow in the testicle suggests testicular torsion and emergent surgical treatment should be performed for detorsion and fixation of the testis. The contralateral testis is usually explored and fixated also.
If surgical treatment is not available in a timely manner, then detorsion can be attempted, after pain relief such as morphine is given. This can be attempted by rotating the long axis of the testis laterally (toward the thigh). Some relief of pain with the testis positioned lower in the scrotum suggests success but the patient should still be evaluated by urology as soon as possible.

Testicular torsion often occurs in prepubertal children as early as day of life 1. It can also occur in utero. If the torsion occurrs earlier than perinatally, it will often present as a small, firm mass that is fixed to the scrotal skin because the tissue is not viable.
Testicular torsion that occurs in utero but perinatally may present with a painless scrotal swelling with an enlarged testis secondary to edema that has not resolved yet.

Learning Point
Scrotal swelling is a common complaint in the pediatric population that often causes much concern by the patient, family and healthcare provider.
Painless scrotal swelling generally does not raise as many alarms because benign causes predominate. However it is important to remember that problems such as tumors may present painlessly.

Painful scrotal swelling or pain in the testis usually raises alarms quickly and boys are brought for evaluation soon after the problem begins.
While there are benign conditions such as insect bites or rashes that can cause pain, the main concern is for testicular torsion which is a surgical emergency.

The differential diagnosis of scrotal swelling includes:

  • Painful scrotum, tender testis
    • Epididymitis
    • Orchitis
    • Testicular torsion
    • Trauma – e.g. hematocoele
  • Painful scotum, non-tender testis
    • Incarcerated hernia
    • Insect bite
    • Rash
    • Torsion of testicular appendix
  • Painless scrotum, testis enlarged
    • Genetic syndrome – e.g. Fragile X
    • Testicular torsion in newborn
    • Tumors of the testis – e.g. primary and secondary
  • Painless scrotum, testis normal sized
    • Henoch-Schonlein purpura
    • Hydrocele
    • Incarcerated hernia
    • Scrotal edema – idiopathic or generalized

Questions for Further Discussion
1. How does torsion of the testicular appendix present?
2. What testicular tumors are common in children?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at MEDLINEplus for this topic: Testicular disorders

and at Pediatric Common Questions, Quick Answers for this topics: Hydrocele and Hernia.

To view current news articles on this topic check Google News.

Fleisher GR, Ludwig S. Synopsis of Pediatric Emergency Medicine. Williams and Wilkins. Baltimore, MD. 1996:197-200.

Illingworth RS. Common Symptoms of Disease in Children. Blackwell Scientific Publications: Oxford. 1998:329-331.

Minevich E, Tackett L. Testicular Torsion. eMedicine. Available from the Internet at http://www.emedicine.com/med/topic2780.htm (rev. 7/20/2005, cited 4/10/2006).

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effecively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.

    7. All medical and invasive procedures considered essential for the area of practice are competency performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

    Donna M. D’Alessandro, MD
    Associate Professor of Pediatrics, Children’s Hospital of Iowa

    May 15, 2006