Appendix of the epididymis
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.
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.
This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)