IS Case 102: Acute Epididymo-orchitis

Wade Hedegard, MD

Imaging Sciences URMC 2008
Publication Date: 2009-05-20


Patient is a 22-year-old male with acute scrotal pain, swelling and erythema.


Grayscale and Doppler ultrasound of the scrotum demonstrate an enlarged right epididymis with asymmetrically increased Doppler blood flow. Right testicular involvement is also identified by mild testicular enlargement and a hyperemic appearance to the testicle with increased Doppler flow. A reactive hydrocele is also present.


Acute Epididymo-orchitis


Acute epididymitis is the most common condition that causes acute scrotal pain in postpubertal men. Distinguishing between acute epididymitis and testicular torsion is essential as they have drastically different treatments. While torsion often requires surgical intervention, epididymitis can be treated with antibiotics. Acute epididymitis usually is due to a lower urinary tract infection or sexually transmitted disease. Common organisms include Chlamydia trachomatis, Neisseria gonorrhoeae, Escherichia coli, Pseudomona, Klebsiella and Proteus. Rare causes include tuberculosis, sarcoidosis, brucellosis, and leprosy. The symptoms include increasing pain, fever, dysuria and/or urethral discharge. Approximately 20-40% of patients with epididymitis also develop concurrent orchitis via direct spread. Complications of epididymitis and/or epididymo-orchitis include infarction, abscess, pyocele, atrophy and infertility.

The sonographic diagnosis of epididymitis is made when there is epididymal enlargement, heterogeneous echotexture, increased Doppler flow, and/or scrotal thickening. Testicular involvement may be demonstrated by testicular enlargement, heterogeneous echotexture of testicle, and/or increased Doppler flow. If there is heterogeneous echotexture to the testicle, a follow-up ultrasound should be performed to demonstrate resolution and ensure that the pattern is not secondary to tumor, metastasis or infarction. Incidentally, up to 10% of testicular tumors present as epididymo-orchitis


  1. Rumack CM, Wilson SR, Johnson J-A, Charboneau JW (eds). Diagnostic Ultrasound, 3rd. Ed., Elsevier Health Sciences, 2005:877-881.
  2. Dogra V, Rubens DJ (eds). Ultrasound Secrets. Philadelphia, PA: Hanley and Belfus; 2004:251-253.

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