The appendix of the epididymis (or pedunculated hydatid) is a small stalked appendage (sometimes duplicated) on the head of the epididymis. It is usually regarded as a detached efferent duct.

Appendix of the epididymis
The right testis, exposed by laying open the tunica vaginalis (appendix of epididymis labeled at center right)
Details
Precursor	Wolffian duct
Identifiers
Latin	appendix epididymidis
Anatomical terminology [edit on Wikidata]

This structure is derived from the Wolffian duct (mesonephric duct) as opposed to the appendix testis which is derived from the Müllerian duct (paramesonephric duct) remnant.