Acute epididymitis with abundant fibrinopurulent exudate in the tubules.
Adult human testicle with epididymis: A. Head of epididymis, B. Body of epididymis, C. Tail of epididymis, and D. Vas deferens
Doppler ultrasound of epididymitis, seen as a substantial increase in blood flow in the left epididymis (top image), while it is normal in the right (bottom image). The thickness of the epididymis (between yellow crosses) is only slightly increased.
Histopathology image of inflamed epididymis and testis
Scrotal ultrasound showing calcifications and cysts in a case of chronic epididymis.

Medical condition characterized by inflammation of the epididymis, a curved structure at the back of the testicle.

- Epididymitis

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Inflammation of the testes.

Doppler ultrasound of the scrotum, in the axial plane, showing orchitis (as part of epididymo-orchitis) as hypoechogenic and slightly heterogenic left testicular tissue (right in image), with an increased blood flow. There is also swelling of peritesticular tissue.

It can also involve swelling, pains and frequent infection, particularly of the epididymis, as in epididymitis.


Part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators.

The cardinal signs of inflammation include: pain, heat, redness, swelling, and loss of function. Some of these indicators can be seen here due to an allergic reaction.
Micrograph showing granulation tissue. H&E stain.
Infected ingrown toenail showing the characteristic redness and swelling associated with acute inflammation
Neutrophils migrate from blood vessels to the infected tissue via chemotaxis, where they remove pathogens through phagocytosis and degranulation
Inflammation is a process by which the body's white blood cells and substances they produce protect us from infection with foreign organisms, such as bacteria and viruses. The (phagocytes) white blood cells are a nonspecific immune response, meaning that they attack any foreign bodies. However, in some diseases, like arthritis, the body's defense system the immune system triggers an inflammatory response when there are no foreign invaders to fight off. In these diseases, called autoimmune diseases, the body's normally protective immune system causes damage to its own tissues. The body responds as if normal tissues are infected or somehow abnormal.
Asthma is considered an inflammatory-mediated disorder. On the right is an inflamed airway due to asthma.
Colitis (inflammation of the colon) caused by Crohn's Disease.
Acute appendicitis
Acute dermatitis
Acute infective meningitis
Acute tonsillitis



Tube that connects a testicle to a vas deferens in the male reproductive system.

Adult human testicle with epididymis: A. Head of epididymis, B. Body of epididymis, C. Tail of epididymis, and D. Vas deferens
Human male reproductive system
Schematic drawing: cross-section through a testicle
Micrograph of epididymis - H&E stain
Deep dissection of epididymis

An inflammation of the epididymis is called epididymitis.

Testicular cancer

Cancer that develops in the testicles, a part of the male reproductive system.

7.4 × 5.5-cm seminoma in a radical orchiectomy specimen.
Image showing the first sign of testicular cancer
Micrograph (high magnification) of a seminoma. H&E stain.
Mixed germ cell tumor containing embryonal carcinoma, seminoma, and yolk sac tumor. The embryonal carcinoma component (upper left, upper right, and lower left) shows pseudoglandular growth with high-grade features of large, epithelioid, anaplastic cells with prominent nucleoli, indistinct cell borders with nuclear overlapping, pleomorphism, and frequent mitoses. The seminoma component (upper center) shows large, round-polyhedral cells with distinct cell membranes, abundant clear/watery cytoplasm, large central nuclei and prominent nucleoli. The yolk sac component (lower right, hugging the embryonal component) exhibits microcystic/reticular growth pattern.
Relative incidences of testicular tumors.

Epididymitis or epididymoorchitis


Elective surgical procedure for male sterilization or permanent contraception.

Open-ended vasectomy

Post-vasectomy pain can be constant orchialgia or epididymal pain (epididymitis), or it can be pain that occurs only at particular times such as with sexual intercourse, ejaculation, or physical exertion.


Sexually transmitted infection caused by the bacterium Chlamydia trachomatis.

Pap smear showing C. trachomatis (H&E stain)
Inflammation of the cervix from chlamydia infection characterized by mucopurulent cervical discharge, redness, and inflammation
A white, cloudy or watery discharge may emerge from the tip of the penis.
Conjunctivitis due to chlamydia
Chlamydia trachomatis inclusion bodies (brown) in a McCoy cell culture

Symptoms in men may include discharge from the penis, burning with urination, or pain and swelling of one or both testicles.


Sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae.

Gonococcal lesion on the skin
An infant with gonorrhea of the eyes
Neisseria gonorrhoeae in pus from a case of gonorrhoea in a man (Gram stain)
Penicillin entered mass production in 1944 and revolutionized the treatment of several venereal diseases.
Gonorrhea rates, United States, 1941–2007
During World War II, the U.S. government used posters to warn military personnel about the dangers of gonorrhea and other sexually transmitted infections.

Complications in women include pelvic inflammatory disease and in men include inflammation of the epididymis.


Male reproductive gland or gonad in all bilaterians, including humans.

Diagram of inner structures of testicles
Animation of the migration of spermatozoa from their origin as germ cells to their exit from the vas deferens. A) Blood vessels; B) Head of epididymis; C) Efferent ductules; D) Seminiferous tubules; E) Parietal lamina of tunica vaginalis; F) Visceral lamina of tunica vaginalis; G) Cavity of tunica vaginalis; H) Tunica albuginea; I) Lobule of testis; J) Tail of epididymis; K) Body of epididymis; L) Mediastinum; M) Vas deferens.
Male gonad (testes, left) and female gonad (ovaries, right)
Transverse section through the left side of the scrotum and the left testis
Cross section of rabbit testis, photographed in bright-field microscopy at 40× magnification
Testicle hanging on cremaster muscle. These are two healthy testicles. Heat causes them to descend, allowing cooling.
A healthy scrotum containing normal size testes. The scrotum is in tight condition. The image also shows the texture.
Testicle of a cat: 1: Extremitas capitata, 2: Extremitas caudata, 3: Margo epididymalis, 4: Margo liber, 5: Mesorchium, 6: Epididymis, 7: testicular artery and vene, 8: Ductus deferens
Testis surface
Testis cross section
The right testis, exposed by laying open the tunica vaginalis.
Microscopic view of Rabbit testis 100×

Epididymitis, a painful inflammation of the epididymis or epididymides frequently caused by bacterial infection but sometimes of unknown origin.

Neisseria gonorrhoeae

Species of Gram-negative diplococci bacteria isolated by Albert Neisser in 1879.

A Gram stain of a urethral exudate showing typical intracellular Gram-negative diplococci, which is diagnostic for gonococcal urethritis
Thayer–Martin agar is selective for growth of Neisseria species. Further testing (oxidase, Gram stain, carbohydrate use) is needed to differentiate N. gonorrhoeae from N. meningitidis.
Carbohydrate utilization of Neisseria gonorrhoeae: N. gonorrhoeae will oxidise glucose, not maltose, sucrose, or lactose; N. meningitidis ferments glucose and maltose.
The growth of N. gonorrhoeae colonies on New York City agar, a specialized and selective medium for gonococci

Infection may spread from the urethra in the penis to nearby structures, including the testicles (epididymitis/orchitis), or to the prostate (prostatitis).

Inguinal hernia

Hernia of abdominal-cavity contents through the inguinal canal.

Diagram of an indirect, scrotal inguinal hernia (median view from the left).
Frontal view of an inguinal hernia (right).
An incarcerated inguinal hernia as seen on cross sectional CT scan
A frontal view of an incarcerated inguinal hernia (on the patient's left side) with dilated loops of bowel above.
An inguinal hernia which contains part of the bladder. Bladder cancer also present.
Ultrasound image of inguinal hernia. Moving intestines in inguinal canal with respiration.
Ultrasound of an indirect hernia containing fat, with testicle seen at right.
T2 weighted MRI of the same case (done for another purpose), also demonstrating fat content.
Surgical incision in groin after inguinal hernia operation
Illustration of an inguinal hernia.
Different types of inguinal hernias.
Inguinal fossae