Appendix of testis
The right testis, exposed by laying open the tunica vaginalis (appendix of testis is labeled at right)
Details
Precursor	Müllerian duct
Artery	Testicular artery
Vein	Testicular vein, Pampiniform plexus
Identifiers
Latin	appendix testis
TA98	A09.3.02.010
TA2	3612
FMA	19846 19846, 19846
Anatomical terminology [edit on Wikidata]

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]}

Clinical significance

Torsion

The appendix of testis can, occasionally 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.^[1]