Epididymal appendix
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At the time the article was created Vasileios Rafailidis had no recorded disclosures.
View Vasileios Rafailidis's current disclosuresAt the time the article was last revised Henry Knipe had the following disclosures:
- Micro-X Ltd, Shareholder (past)
These were assessed during peer review and were determined to not be relevant to the changes that were made.
View Henry Knipe's current disclosures- Appendix epididymis
- Appendix of the epididymis
- Epididymal appendages
- Cystic appendix epididymis
Epididymal appendices, also known as appendix of the epididymis or appendix epididymis, are testicular appendages and are less common than appendix testes 4.
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Epidemiology
Epididymal appendices are reported to occur at 12.5% (range 6-17.6%) on ultrasound and in ~33% of post-mortem studies 3,4.
Clinical presentation
Normally, epididymal appendices are of no clinical significance, but when torsed, they can cause an acute scrotum 2,4.
Pathology
Epididymal appendices are a developmental remnant of the mesonephric (Wolffian) duct 4. They are more commonly unilateral than bilateral 4.
They are, on average, 6.5 mm (range 3-11 mm) in size. Most commonly, they have a pedunculated morphology with a thin stalk measuring 5 mm in length 2,4. Approximately one-third are cystic 4.
If the pedicle torts, which results in infarction, the appendage may detach and wander inside the scrotum, appearing as minute mobile particles ("loose bodies") 3.
Radiographic features
Ultrasound
Ultrasonography with a high-frequency linear transducer can reliably evaluate the appendix testis, including its vascularity. In general, the epididymis appendix is best seen when floating in a hydrocele.
The appendix epididymis, similarly to the appendix testis, is most commonly round or ovoid and pedunculated with a stalk, although they are also commonly sessile 1,4. They appear isoechoic to the testicular or epididymal parenchyma 4. When cystic they are most commonly unilocular although can have septations 4. Sometimes, calcifications may be found ref.
Color Doppler signal is normally absent 5.
Differential diagnosis
When torsed, it is a cause of acute scrotum and the imaging differential diagnosis includes:
References
- 1. Sellars M & Sidhu P. Ultrasound Appearances of the Testicular Appendages: Pictorial Review. Eur Radiol. 2003;13(1):127-35. doi:10.1007/s00330-002-1387-1 - Pubmed
- 2. Baldisserotto M, de Souza J, Pertence A, Dora M. Color Doppler Sonography of Normal and Torsed Testicular Appendages in Children. AJR Am J Roentgenol. 2005;184(4):1287-92. doi:10.2214/ajr.184.4.01841287 - Pubmed
- 3. Valentino M, Bertolotto M, Ruggirello M, Pavlica P, Barozzi L, Rossi C. Cystic Lesions and Scrotal Fluid Collections in Adults: Ultrasound Findings. J Ultrasound. 2011;14(4):208-15. doi:10.1016/j.jus.2011.10.008 - Pubmed
- 4. Kantarci F, Ozer H, Adaletli I, Mihmanli I. Cystic Appendix Epididymis: A Sonomorphologic Study. Surg Radiol Anat. 2005;27(6):557-61. doi:10.1007/s00276-005-0034-3 - Pubmed
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