Contributed by
Children's National Hospital, Washington DC
Sachin Chitalkar, and Dorothy Bulas.
History
A 10-year-old male with Down syndrome presented with intermittent right groin pain for several weeks. Patient was afebrile.
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Question
What is the most reasonable diagnosis?
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Correct answer
Acute epididymitis with epididymal abscess
Discussion
Acute epididymitis is a common cause of scrotal pain and an important consideration in the acute scrotum, where imaging is essential to confirm the diagnosis and exclude testicular torsion. On grayscale ultrasonography, epididymitis typically presents as focal or diffuse epididymal enlargement, most commonly involving the tail, with heterogeneous or hypoechoic echotexture. Associated findings include reactive hydrocele, scrotal wall thickening, and inflammatory changes in surrounding soft tissues. Color Doppler imaging characteristically demonstrates marked epididymal hyperemia, a key feature distinguishing epididymitis from torsion. Complicated cases may show epididymal abscess formation as a focal, complex, avascular lesion, as observed in this case. Uncomplicated epididymitis is usually managed conservatively with antibiotics and supportive care.
This patient demonstrated conflicting clinical and imaging findings. The non‑acute presentation; preserved testicular vascularity; and an enlarged, heterogeneous, hyperemic epididymis favored epididymitis; however, the suggestion of a whirlpool sign of the spermatic cord could be concerning for torsion–detorsion. Given these discordant features, surgical exploration was performed. Intraoperatively, no spermatic cord twisting was identified, and testicular vascularity was normal, excluding torsion. The concern for a paratesticular mass such as rhabdomyosarcoma was raised during surgery and decision was taken to proceed with right radical orchidectomy. The histopathology results, however, confirmed inflammatory epididymal mass with exclusion of malignancy.
Differential diagnosis
Epididymitis and testicular torsion are common causes of acute scrotal pain in children and adolescents, while paratesticular rhabdomyosarcoma represents an important malignant consideration in cases presenting with a painless or subacute scrotal mass. Distinguishing among these entities is critical, as management and prognosis differ substantially.
Testicular torsion is a urologic emergency caused by twisting of the spermatic cord, leading to impaired testicular perfusion. Ultrasound may demonstrate decreased or absent intratesticular blood flow; however, preserved flow can be seen in torsion–detorsion events, with the whirlpool sign of the spermatic cord remaining a highly specific finding.
Paratesticular rhabdomyosarcoma is a rare malignant tumor arising from extratesticular structures, most commonly the spermatic cord or epididymis. Imaging typically reveals a solid, heterogeneous, hypervascular extratesticular mass displacing the testis. Due to overlapping imaging features with inflammatory conditions, definitive diagnosis often requires surgical exploration and histopathological confirmation.
References
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