The epididymis (from the Greek epididumis) is an organ belonging to the male reproductive system located at the level of the wall of the testis.

Position. There are two epididymics. Each epididymis borders the upper and posterior surface of each testis (1) (2).

Structure. The epididymis consists of a retracted tube, called the epididymal duct, measuring on average six meters in length (1). It consists of three parts (2):

• The head of the epididymis which originates on the upper part of the testis;
• The body of the epididymis which is the intermediate part extending on the dorsal face of the testis;
• The tail of the epididymis which constitutes the last part extending through the vas deferens.

Envelopee. The epididymis and testis are contained in the scrotum, the wall of which forms the tunica vagina (1).

Points d’attaches. The epididymis is connected to the testis by the upper and lower epididymal ligaments (2).

Vascularization. The epididymis is supplied by the testicular arteries (1).

Sperm maturation. Spermatogenesis takes place within the testis. Then the sperm are collected within the epididymis where they complete their maturation (1).

Sperm storage and flow. Sperm are stored mainly at the tail of the epididymis but also at the level of the body. Contractions of the muscular wall of the epididymis will transport sperm to the vas deferens (2).

Protection of the epididymis. The epididymis and testis are protected from shock by the scrotum (1).

Epididymite. This pathology corresponds to an inflammation of the epididymis. It is often associated with another inflammation in the prostate or urethra. This inflammation may be due to a bacterial infection. It manifests as feverish rashes, redness, swelling and sharp pain in the testicles (2).

Cyst of the epididymis. A cyst is a cavity filled with fluid that can develop especially in the head of the epididymis. The development of a cyst can cause discomfort and pain in the testicles (3).

Testicular cancer. Malignant tumors can develop in the testis and epididymis. These tumors can remain silent for a long time without causing particular pain. They are most often revealed by palpation by noting the presence of a hard mass (4).

Medical treatment. Depending on the pathology diagnosed, certain drugs may be prescribed such as antibiotics in the case of epididymitis.

Surgical treatment. Depending on the pathology diagnosed and its evolution, a surgical intervention may be performed such as an epididymectomy, partial or total removal of the epididymis.

Chemotherapy, radiotherapy, targeted therapy. Depending on the stage of the cancer, the treatment of cancer cells can be carried out using chemotherapy, radiotherapy or even targeted treatment.

Physical examination. First, a clinical examination is performed to assess the patient’s symptoms. Palpation may be done to identify the presence or absence of a hard, irregular body, which may be a sign of tumor development.

Medical imaging exam. An ultrasound may be done to confirm or complete a diagnosis.

Dosage of markers. Blood tests can be done, especially to reveal tumor markers.

In 2009, a team of CNRS researchers unveiled the discovery of a protein produced by the epididymis whose role would be to protect spermatozoa from oxidation. This discovery could advance the processes used in medically assisted reproduction (5).