Appendix of testis
The right testis, exposed by laying open the tunica vaginalis (appendix of testis is labeled at right)
PrecursorMüllerian duct
Latinappendix testis
FMA19846 19846, 19846
Anatomical terminology
Scrotal ultrasonography of an 85-year-old man with hydrocele, making the appendix of the testicle clearly distinctive as a 4 mm outpouching at upper left in image. Doppler shows some blood flow.

The appendix testis (or hydatid of Morgagni) is a vestigial remnant of the Müllerian duct, present on the upper pole of the testis and attached to the tunica vaginalis. It is present about 90% of the time[citation needed] and is homologous to the fallopian tubes in females.[1]

Clinical significance


The appendix of testis can, occasionally, undergo torsion (i.e. become twisted), causing acute one-sided testicular pain and may require surgical excision to achieve relief. One third of patients present with a palpable "blue dot" discoloration on the scrotum. This is nearly diagnostic of this condition. If clinical suspicion is high for the serious differential diagnosis of testicular torsion, a surgical exploration of the scrotum is warranted. Torsion of the appendix of testis occurs at ages 0–15 years, with a mean at 10 years, which is similar to that of testicular torsion.[2]

See also


  1. ^ Carreon, Chrystalle; Huff, Dale S. M.; Ruchelli, Eduardo D.; Ernst, Linda M. (2019). Color Atlas of Human Fetal and Neonatal Histology. Springer International Publishing. p. 142. ISBN 978-3-03011-425-1. Retrieved September 16, 2023.
  2. ^ Jason S Chang (7 June 2022). "Torsion of the Appendices and Epididymis". Medscape. Updated: Oct 20, 2016. Citing:
    Nason, Gregory J; Tareen, Farhan; McLoughlin, Danielle; McDowell, Dermot; Cianci, Fiona; Mortell, Alan (2013). "Scrotal exploration for acute scrotal pain: A 10-year experience in two tertiary referral paediatric units". Scandinavian Journal of Urology. 47 (5): 418–422. doi:10.3109/00365599.2012.752403. ISSN 2168-1805. PMID 23281617. S2CID 3072304.