Positively Painful Private Parts III: Torsion of the appendix testis and appendix epididymis

Another potential cause of acute testicular pain involves vestigial structures that you may remember in the deepest recesses of you medschool brain.

Appendix testis

Derived from the Müllerian system

They are paired embryonic structures that eventually regress in males and form the Fallopian tubes, uterus, cervix and upper third of the vagina in girls.

Appendix epididymis

Derived from the Wolffian system

These paired embryonic structures eventually become the epididymis, vas deferens, and seminal vesicles.

"Gray1148". Licensed under Public domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Gray1148.png#mediaviewer/File:Gray1148.png

“Gray1148”. Licensed under Public domain via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:Gray1148.png#mediaviewer/File:Gray1148.png

These ‘lil nubbins are clinically important because they can torse and lead to acute testicular pain. This usually occurs between age 7 and 12 years. The initial pain is usually severe because the aforementioned nubbin is ischemic which leads to infarction and necrosis. Ischemia hurts. You may see a reactive hydrocele, but the pathognomonic physical exam finding, which I see once every 5-6 years is the “blue dot sign.”

Blue dot sign: Ischemic/infarcted embryonic remnant is seen on the right side through the thin scrotal wall. Attribution: dontforgetthebubbles.com

You can diagnose this clinically if the patient is in the right age bracket and has a blue dot sign. Otherwise get an ultrasound if you cannot rule out torsion of the testis. The pain is expected to last 5-10 days and will be most intense for the first 2-3 days. Management is conservative and consists of:

  • Analgesics
  • Rest
  • Scrotal support
By |2016-12-14T12:56:51+00:00September 29th, 2014|Urology|

About the Author:

Brad Sobolewski, MD, MEd is an Associate Professor of Pediatric Emergency Medicine and an Assistant Director for the Pediatric Residency Training Program at Cincinnati Children's Hospital Medical Center. He is on Twitter @PEMTweets and authors the Pediatric Emergency Medicine site PEMBlog. All views are strictly my own and not official medical advice.


  1. Ted Ferenczy September 29, 2014 at 10:10 AM

    Even if there was a classic “blue dot sign” in the right age group I think it would be pretty ballsy to not get an ultrasound. It’s a minimally invasive test that can confirm your diagnosis and document perfusion to the testes!

  2. Brad Sobolewski, MD, MEd September 29, 2014 at 5:39 PM

    Thanks for the reply Ted. It is interesting how medicine is practiced differently in the clinic vs urgent care vs ED. If the patient is really comfortable and the diagnosis is certain based on your exam I would think that holding off on the ultrasound is ok especially if you didn’t have 24 access to a sonographer. Would you feel similarly with a teenage male who is sexually active in whom you susp ct epididymis is based on exam?

    Ps I caught the pun – unintended or not 🙂

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