Epididymitis (inflammation of the epididymis; see the image below) is a significant cause of morbidity and is the fifth most common urologic diagnosis in men aged 18-50 years.[1] Epididymitis must be differentiated from testicular torsion, which is a true urologic emergency.
View Image | Color Doppler sonogram of the left epididymis in a patient with acute epididymitis. The image demonstrates increased blood flow in the epididymis resu.... |
The following history findings are associated with acute epididymitis and orchitis:
The following history findings are associated with chronic epididymitis:
The following history findings are associated with mumps orchitis:
Physical examination findings may fail to distinguish acute epididymitis from testicular torsion. Physical findings associated with acute epididymitis may include the following:
Findings associated with orchitis may include the following:
See Presentation for more detail.
The following laboratory studies may be indicated for suspected epididymitis:
Although epididymitis may often be an infectious process, cultures commonly fail to demonstrate any identifiable infection.
Imaging studies that may be considered to evaluate structural abnormalities and help distinguish acute epididymitis from testicular torsion include the following:
Other measures that may be useful for evaluation include the following:
See Workup for more detail.
Pharmacologic treatment of epididymitis may include the following:
In addition to antibiotics (except in viral epididymitis), the mainstays of supportive therapy for acute epididymitis and orchitis are as follows:
Surgical options include the following:
See Treatment and Medication for more detail.
Go to Acute Epididymitis for complete information on emergent management of epididymitis.
Complications
Complications associated with acute epididymitis and bacterial orchitis include the following:
With regard to the last item above, true local pain can be distinguished from referred pain by spermatic cord injection with 1% lidocaine. Refractory pain that is not improved by analgesics has also been managed by denervation of the spermatic cord.
With regard to fertility problems, sterility is uncommon after acute epididymitis, although the true incidence is unknown. Disturbances in the sperm quality secondary to leukocytospermia and inflammation are usually transient. More important is the far less common azoospermia, which is caused by the epididymal duct obstruction observed in men with untreated or improperly treated epididymitis. The incidence of this condition is unknown.
Complications associated with mumps orchitis include the following:
The patient should limit activity, and the scrotum should be immobilized.
Stress that the course of antibiotics needs to be completed, and also stress the need for screening tests for and treatment of comorbid sexually transmitted diseases for the patient and his sexual partners.
For patient education information, see the Men's Health Center, the Infections Center, and the Sexual Health Center, as well as Epididymitis, Inflammation of the Testicle (Orchitis), Mumps, and Sexually Transmitted Diseases (STDs).
The epididymis is a coiled tubular structure located along the posterior aspect of the testis, connecting the efferent ducts of the testis to the vas deferens. It allows for the storage, maturation, and transport of sperm
The image below is a diagram of the testis and epididymis.
View Image | Cross-section illustration of a testicle and epididymis. A: Caput or head of the epididymis. B: Corpus or body of the epididymis. C: Cauda or tail of .... |
The exact etiology of acute epididymitis is unclear; however, it is believed to be caused by the retrograde passage of urine from the prostatic urethra to the epididymis via the ejaculatory ducts and vas deferens. Obstruction of the prostate or urethra and congenital anomalies create a predisposition for reflux. Normally, the oblique angle of the ejaculatory ducts through the dense prostatic tissue prevents reflux. Fifty-six percent of men older than 60 years who have epididymitis exhibit concurrent bladder outlet obstruction (BOO), such as a urethral stricture or benign prostatic hyperplasia (BPH).
Reflux may also be induced by Valsalva maneuvers or strenuous exertion. This can be seen in athletes such as weight lifters. Epididymitis is commonly found to develop during strenuous exertion in conjunction with a full bladder.
Instrumentation and indwelling catheters are common risk factors for acute epididymitis.
Epididymitis may be accompanied by urethritis or prostatitis.
Infection that is severe and extends to the adjacent testicle is termed acute epididymo-orchitis.[20] The etiology of acute epididymo-orchitis varies with the age of the patient and may be a bacterial, nonbacterial infectious, noninfectious, or idiopathic process.
Infections with urinary coliforms (eg, E coli, Pseudomonas species, Proteus species, Klebsiella species) are the most common cause in children and in men older than 35 years. Ureaplasma urealyticum, Corynebacterium species, Mycoplasma species, and Mima polymorpha have also been isolated. Systemic Haemophilus influenzae and Neisseria meningitides infections are rare. In men who are the insertive partner during anal intercourse, infections with coliform bacteria are also a common etiology.[2]
Chlamydia is the most common cause in sexually active men younger than 35 years (accounting for up to 50% of cases, although laboratory evidence of chlamydia may be absent in up to 90% of cases).[3] Infections with the following pathogens also occur in this population:
Tuberculous epididymitis can occur in endemic areas and is still the most common form of urogenital tuberculosis (TB). It is believed to spread hematogenously and often involves the kidneys.
Epididymo-orchitis may develop following bacillus Calmette-Guérin (BCG) treatment for superficial bladder cancer (at a rate of 0.4%).
Viral epididymitis is thought to be the predominant etiology of pediatric epididymitis. It is defined by the absence of pyuria. Although mumps is the most common viral cause of epididymitis, coxsackievirus A, varicella, and echoviral infections have also been identified.
Other rare infections (eg, brucellosis,[21] coccidioidomycosis, blastomycosis, cytomegalovirus [CMV], candidiasis, CMV in human immunodeficiency virus [HIV] infection, nontuberculous mycobacteria) have been implicated in epididymitis but usually occur in immunocompromised hosts.
Roughly 1 in 1000 men who undergo vasectomy describe a postvasectomy pain syndrome of chronic, dull, aching pain in the epididymis and testicle. The pain is most likely secondary to chronic epididymal congestion of sperm and fluid that continues to be produced after the vasectomy. The epididymis can become distended from back pressure of this fluid, particularly following the close-ended vasectomy technique. When sperm extravasates from the end of the vas deferens, such as can occur in the open-ended vasectomy technique, a sperm granuloma may develop, with a resulting inflammatory reaction.
Men older than 40 years may have BOO (eg, BPH) or a urogenital malformation that predisposes them to urethrovasal reflux and the development of epididymitis. Such reflux can also be induced iatrogenically after certain surgical procedures, such as transurethral resection of the ejaculatory ducts, resulting in epididymitis. It can also be a result of heavy physical activity such as weight lifting.
In children, infection is less common an etiology. One study of a pediatric emergency department found only 4 (4.1%) of 97 children diagnosed with epididymitis had a positive urine culture.[4] Children may have various congenital abnormalities or functional voiding problems that increase the risk of reflux into the ejaculatory ducts. For example, epididymitis may be related to urethral abnormalities, an ectopic ureter, an ectopic vas deferens, detrusor sphincter dyssynergia, or vesicoureteral reflux. In rare cases, children with anorectal malformations and resulting rectourinary fistulae may have resulting bacterial causes of epididymitis.[5]
Acute epididymo-orchitis has been described in 12-19% of individuals with Behçet syndrome. It is also associated with Henoch-Schönlein purpura in the pediatric population, most likely as part of a systemic inflammatory process. Up to 38% of patients with Henoch-Schönlein have scrotal involvement (range, 2-38%).
Amiodarone epididymitis is secondary to high drug concentrations, usually in the head of the epididymis, and can occur in up to 3-11% of patients taking the drug. This is a dose-dependent phenomenon and typically occurs at dosages greater than 200 mg daily. Epididymal levels of the drug are up to 300 times those of the serum, resulting in antiamiodarone HCl antibodies that subsequently attack the epididymis, resulting in the symptoms of epididymitis. Histologic analysis reveals focal fibrosis and lymphocytic infiltration of epididymal tissues.
Sarcoidosis affects the genitourinary system in up to 5% of cases, typically presenting with epididymal nodules. Trauma to the scrotum can also be a precipitating event, while some cases are idiopathic.
The etiology of chronic epididymitis includes the following:
Causes of acute orchitis include the following:
With regard to a viral etiology, roughly one third of postpubertal boys with mumps have concomitant orchitis. Coxsackievirus type A, varicella, and echoviral, adenoviral, enteroviral, influenzal, and parainfluenzal infections are rare.
An estimated 1 in 1000 men develop epididymitis annually, and acute epididymitis accounts for more than 600,000 medical visits per year in the United States. Epididymitis is the most common cause of intrascrotal inflammation. Incidence is less than 1 case in 1,000 males per year. However, chronic epididymitis may account for up to 80% of patients presenting with scrotal pain in the outpatient setting.
Epididymitis is the fifth most common urologic diagnosis in men ages 18-50 years. The average age of a patient with chronic epididymitis is 49 years. Patients often experience symptoms for 5 years before diagnosis.
Acute epididymitis most commonly occurs in men aged 20-59 years (43% in men aged 20-39 y and 29% in men aged 40-59 y). Childhood (prepubertal) epididymitis is rare; testicular torsion is more common in this age group.
In a study from Spain, epididymitis accounted for 28.4% of cases of acute, intense scrotal pain in adults presenting to an emergency department at one hospital. Orchiepididymitis comprised 28.7% of cases. The mean age of these patients was 40.2 ± 17.3 years.[6]
Structural urologic abnormalities are common in children and in men older than 40 years with acute epididymitis. Adults usually have BOO or urethral stricture or may have had previous urologic surgery on their urethra, altering their anatomy and predisposing them to infection. Children may have urethral abnormalities, such as a prostatic utricle, urethral duplication, posterior urethral valves, or urethrorectal fistula, or other anomalies, such as an ectopic ureter, ectopic vas deferens, detrusor sphincter dyssynergia, or vesicoureteral reflux.
Siegel et al found that 47% of prepubertal boys with epididymitis had associated urogenital abnormalities, including ectopic vas deferens or ureters, and urethral abnormalities.[7]
Mumps orchitis occurs in 20-40% of postpubertal boys with mumps but is rare in prepubertal boys.
Hongo et al reported that older age; previous history of diabetes mellitus and fever; and higher white blood cell count, C-reactive protein level, and blood urea nitrogen level were independently associated with severity in Japanese patients with epididymitis. These authors created an algorithm that proved to have 98.8-100% specificity for predicting severe epididymitis.[8]
Pain improves within 1-3 days, but induration may take several weeks or months to resolve. Infection of the epididymis can lead to the formation of an epididymal abscess. In addition, progression of the infection can lead to involvement of the testicle, causing epididymo-orchitis or a testicular abscess. Sepsis is a potential consequence of severe infection. Bilateral epididymitis may result in sterility due to occlusion of the ductules from peritubular fibrosis.
Patients with epididymitis secondary to a sexually transmitted disease have 2-5 times the risk of acquiring and transmitting HIV.[9] All sexual partners of patients with epididymitis secondary to a sexually transmitted disease need referral to ensure that they receive adequate testing and treatment.
The following history findings are associated with acute epididymitis and orchitis:
The following history findings are associated with chronic epididymitis:
The following history findings are associated with mumps orchitis:
Younger patients or any patient with a sexually transmitted epididymitis may note symptoms related to urethritis.
A recent history of endourethral instrumentation or urinary tract infection is more common in older patients with epididymitis.
Tenderness and induration first occur in the epididymal tail, which may be the first site of reflux via the vas deferens. It then appears to spread to the body, head, and even the spermatic cord (funiculitis) or the ipsilateral testis (epididymo-orchitis). Acute epididymitis is bilateral in 5-10% of affected patients.
When checking for the Prehn sign during an examination, the affected hemiscrotum is elevated. This action relieves the pain of epididymitis but exacerbates the pain of torsion (positive Prehn sign). The elevation takes the weight of the testis off the epididymal suspension.
Physical examination findings may fail to distinguish acute epididymitis from testicular torsion. A normal cremasteric reflex indicates that testicular torsion is less likely.
Erythema and mild scrotal cellulitis may be present, while a reactive hydrocele is common in patients with advanced epididymo-orchitis, complicating scrotal examination. Postpubertal individuals with acute epididymitis frequently have associated bacterial prostatitis and/or seminal vesiculitis.
TB can cause focal epididymitis, a draining sinus, or beading of the vas deferens with extensive involvement. Orchitis rarely occurs without epididymitis in TB.
In children, epididymitis may be related to an underlying congenital anomaly of the urogenital tract, such as urethral abnormalities, an ectopic ureter, an ectopic vas deferens, detrusor sphincter dyssynergia, or vesicoureteral reflux.
Testicular enlargement, induration, and a reactive hydrocele are common. The epididymis is not tender. Orchitis is found in association with acute epididymitis in 20-40% of cases.
The following laboratory studies may be indicated for suspected epididymitis:
If mumps orchitis is clinically suspected but the diagnosis is in doubt, use immunofluorescent antibody testing to confirm the diagnosis. Urinalysis and culture findings are negative in mumps orchitis.
Amiodarone plasma levels or antibodies are not helpful in the diagnosis of amiodarone-induced epididymitis.
Use imaging studies (see the images below) to help distinguish acute epididymitis from the more ominous testicular torsion. However, clinical judgment must guide interpretation of imaging results, as they are neither 100% sensitive nor specific.
View Image | Scrotal sonogram demonstrating the presence of a hydrocele and an enlarged epididymis in a patient with epididymitis. The echogenic white area is the .... |
View Image | Scrotal sonogram showing the testes adjacent to the inflamed epididymis with a reactive hydrocele. |
Do not allow studies to delay intervention or exploration if testicular torsion is suspected because testicular viability drops significantly with delay. In addition, the clinical evaluation is paramount and imaging studies should be used if the examination findings are indeterminate. Confirmatory imaging is unnecessary in a patient with a clear history consistent with epididymitis; ultrasonographic results are positive in only 69% of patients with clinical epididymitis.
Radiologic studies are recommended in children who have bacteruria and acute epididymitis in order to evaluate for structural abnormalities (found in >50% of these patients). In infants with bacteruria and epididymitis, in whom anatomical abnormalities are more common than in older children, a voiding cystourethrogram (VCUG) and abdominal ultrasonography are recommended. Retrograde urethrography is also indicated to evaluate for urethral stricture disease as symptoms dictate.
Radiologic studies for mumps orchitis are not indicated, although a reactive hydrocele is common. Patients with tuberculous epididymitis[10] require a full workup for systemic TB. This may include chest radiography, renal function tests, or computed tomography (CT) or excretory urography.
Along with radiologic evaluation, cystourethroscopy may be indicated to evaluate for structural abnormalities in children, as radiographic and clinical suspicion dictates.
Go to Epididymis Imaging for complete information on this topic.
Scrotal exploration or aspiration of the epididymis is rarely needed. If it is needed, it is performed by a urologist. Perform a scrotal exploration if torsion or tumor cannot be ruled out and for the complications of acute epididymitis and orchitis (eg, abscess, pyocele, testicular infarction). Diagnosis of intrascrotal disorders is often confirmed during orchiectomy.
The WBC count may be elevated with a left shift (10,000-30,000 cells/μL). A midstream urine culture and Gram stain are useful in guiding therapy. Urinalysis findings are positive for pyuria in only 25% of patients and are sterile in 40-90% of patients.
Obtain a urethral swab culture (before void, after prostate massage) for gonorrheal and chlamydial infections if the patient is in the at-risk age group or if the patient is older than 40 years and not monogamous. Gonorrheal infections often demonstrate gram-negative diplococci on smear, while chlamydial infections can be established in two thirds of cases when only WBCs are seen on smear. A chlamydia polymerase chain reaction (PCR) assay is highly specific and sensitive for chlamydial infection.
Perform blood cultures if the patient is systemically ill.
It is recommended that pediatric patients be evaluated for underlying congenital anomalies via abdominopelvic ultrasonography, voiding cystourethrography, and, in some cases, cystoscopy, especially when the urine culture result is positive. Debate is ongoing as to whether further work-up is necessary only in those with recurrent episodes or also after a first episode of epididymitis or epididymo-orchitis.
Color Doppler ultrasonography is important in the diagnostic workup of epididymitis, not only for diagnosing epididymitis but to rule out testicular torsion. The sensitivity for torsion in color Doppler ultrasonography is 82-100%, and the specificity is 88.9-100%.[11] The sensitivity of color Doppler ultrasonography for epididymitis is 92-100%.[12, 13] This test is the most widely available; however, it is examiner-dependent. The effectiveness of the examination can be limited by pain and patient size (eg, infants). It should also be reserved for patients with indeterminate examination, history, or laboratory workup findings.
Increased blood flow occurs with epididymitis (see the image below); no flow occurs with torsion. Testicular tumors can also appear hyperemic.[14]
View Image | Color Doppler sonogram of the left epididymis in a patient with acute epididymitis. The image demonstrates increased blood flow in the epididymis resu.... |
The examination may reveal epididymal enlargement or a reactive hydrocele of mixed echogenicity (inhomogeneous echogenicity). Use ultrasonography to help detect a scrotal abscess, as well as complications of epididymitis and bacterial or pyogenic orchitis.
Chronic epididymitis is characterized by an enlarged testis and epididymitis, as well as by a thickened tunica vaginalis with a heterogeneous echo pattern and the presence of course calcifications. The testicle may be atrophic and hypoechoic or heterogeneous from testicular infarction secondary to compromise of the testicular blood flow due to intratesticular edema.
Go to Epididymis Imaging for complete information on this topic.
One of the sequelae of epididymitis is segmental, and even global testicular infarction. Contrast-enhanced ultrasonography may help distinguish this situation.[15]
Sensitivity for torsion is 90-100% in technetium-99m (99m Tc) scanning, and specificity is 89-97%. Use99m Tc scanning with imaging every 2 seconds for 2 minutes after injection of the tracer.
Acute epididymitis is characterized by increased tracer uptake, while torsion is characterized by defective uptake in the scrotum. Late torsion may result in inflammation that resembles epididymitis.
The study’s usefulness is limited by availability, cost, and difficulty with interpretation. Hydrocele and abscess cause false-positive results. Spontaneous detorsion and intermittent torsion may cause false-negative results.
Radionuclide scintigraphy is used to assess testicle perfusion, yet it provides little anatomic information. Decreased perfusion suggests torsion. Increased or normal perfusion suggests epididymitis but also may be reported with actual torsion.
In chronic epididymitis, a 4- to 6-week trial of antibiotics for bacterial pathogens, especially against chlamydial infections, is appropriate.
With epididymitis secondary to Chlamydia trachomatis or Neisseria gonorrhoeae, treatment of all sexual partners is necessary in order to limit the rate of recurrence and to achieve maximal cure rates. Reinforce the advisability of condom use in the prevention of sexually transmitted disease.
If an enteric organism is the suspected cause of epididymo-orchitis, fluoroquinolones are the preferred antibiotic, as they have excellent penetration into the testes.[16]
Given the low incidence of urinary tract infections in boys with epididymitis, antibiotic therapy in prepubertal patients can be reserved for young infants and those with pyuria or positive urine culture findings. Because predicting a positive urine culture result is difficult, urine cultures should be obtained on all pediatric patients with epididymitis.[17]
Obtain immediate consultation with a urologist upon suspicion of testicular torsion, scrotal abscess, or failed medical treatment.
Orchiectomy is indicated only for patients with unrelenting epididymal pain, although up to 50% of patients still report phantom postoperative pain. Conduct an epididymotomy infrequently in patients with acute suppurative epididymitis. In rare cases, refractory pain due to chronic epididymitis and orchialgia has been managed with skeletonization of the spermatic cord via subinguinal varicocelectomy. Viral mumps has no surgical indications.
Go to Acute Epididymitis for complete information on this topic.
Guidelines from the Centers for Disease Control and Prevention (CDC) recommend the following regimen for acute epididymitis most likely caused by sexually transmitted chlamydia and gonorrhea[1, 2] :
For acute epididymitis most likely caused by sexually-transmitted chlamydia and gonorrhea and enteric organisms (eg, in men who practice insertive anal sex), CDC recommendations are as follows:
For acute epididymitis most likely caused by enteric organisms (eg, cases that develop after prostate biopsy, vasectomy, and other urinary-tract instrumentation procedures, with sexually transmitted organisms ruled out) CDC recommendations are as follows:
In addition to antibiotics (except in viral epididymitis), the mainstays of supportive therapy for acute epididymitis and orchitis are as follows:
Epididymectomy was once reported to offer a limited chance (at best 50%) of relieving pain caused by chronic epididymitis.
However, a study by Siu et al found that 70% of patients who underwent epididymectomy in the face of chronic epididymal pain (in the setting of postvasectomy pain, obstruction due to radical retropubic prostatectomy or hernia repair, epididymal cysts, or chronic epididymitis) reported pain resolution.[10] In this same study, 91% of patients reported satisfaction with their decision for surgery.
Inhibition of adhesion and fibrosis after epididymectomy for chronic epididymitis improves pain relief, according to a study of 43 patients who still had pain despite conservative treatment.[18] A synthetic physical barrier (hyaluronic acid [HA]/carboxymethylcellulose [CMC]) was used to inhibit adhesion and fibrosis at the operative site in 22 patients; the remaining 21 underwent epididymectomy alone. At 24-week follow-up, 12 patients (57.1%) in the HA/CMC group were pain free, compared with 3 patients (15.8%) in the surgery-only group. HA/CMC was not associated with any adverse effects.
It has been found that epididymectomy may be more effective in men post vasectomy compared with those who have not undergone vasectomy.[19]
Despite these findings, it is still suggested that surgery be reserved only for refractory cases. Concern is that pain relief is only transient and followed by pain recurrence or transfer of symptoms to the contralateral testicle.
The possibility of fertility sequelae should also be discussed with the patient.
Clinical Context: This is a third-generation cephalosporin with broad-spectrum gram-negative activity. Ceftriaxone has lower efficacy against gram-positive organisms and higher efficacy against resistant organisms. It arrests bacterial growth by binding to 1 or more penicillin-binding proteins.
Clinical Context: Doxycycline is used to treat C trachomatis infection. It inhibits protein synthesis and thus bacterial growth by binding to 30S and possibly 50S ribosomal subunits of susceptible bacteria.
Clinical Context: Azithromycin acts by binding to 50S ribosomal subunit of susceptible microorganisms and blocks dissociation of peptidyl transfer ribonucleic acid (tRNA) from ribosomes, causing RNA-dependent protein synthesis to arrest. Nucleic acid synthesis is not affected.
Azithromycin concentrates in phagocytes and fibroblasts, as demonstrated by in vitro incubation techniques. In vivo studies suggest that concentration in phagocytes may contribute to drug distribution to inflamed tissues. Azithromycin is used for the treatment of gonococcal infections, chlamydia, or both.
Clinical Context: Ofloxacin penetrates the prostate well and is effective against C trachomatis. It is no longer recommended to use fluoroquinolones to treat gonococcal infections secondary to a high rate of resistance. Ofloxacin is a pyridine carboxylic acid derivative with broad-spectrum bactericidal effect.
Clinical Context: This agent is for bacterial infections. Ciprofloxacin is no longer recommended for gonococcal and nongonococcal infections, such as chlamydia, given their incomplete coverage and increased rate of resistance.
Clinical Context: This is for the empiric treatment of nonspecific bacterial infection.
Clinical Context: Levofloxacin is excreted in the urine and is effective against C trachomatis. It is no longer recommended to use fluoroquinolones to treat gonococcal infections secondary to a high rate of resistance. Levofloxacin is a pyridine carboxylic acid derivative with broad-spectrum bactericidal effect.
Clinical Context: Ampicillin is used for the treatment of systemic illness warranting hospitalization. It is a broad-spectrum penicillin, and it interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms. Ampicillin is an alternative to amoxicillin when the patient is unable to take medication orally.
Until recently, the HACEK bacteria were uniformly susceptible to ampicillin. Recently, however, beta-lactamase–producing strains of HACEK have been identified.
Clinical Context: Gentamicin is used for the treatment of systemic illness warranting hospitalization. It is an aminoglycoside antibiotic for coverage of gram-negative bacteria, including pseudomonal species. It is synergistic with beta-lactamase against enterococci. It interferes with bacterial protein synthesis by binding to the 30S and 50S ribosomal subunits.
Dosing regimens are numerous and are adjusted based on creatinine clearance and changes in the volume of distribution, as well as the body space into which the agent needs to distribute. Gentamicin may be given IV/IM. Each regimen must be followed by at least a trough level drawn on the third or fourth dose, 0.5 hour before dosing; a peak level may be drawn 0.5 hour after a 30-minute infusion.
Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.
Clinical Context: These agents are used to treat tuberculous epididymo-orchitis
Clinical Context: This is an isonicotinic acid hydrazide (INH), which is part of the triple-drug regimen.
Clinical Context: Pyrazinamide is a pyrazine analog of nicotinamide that may be bacteriostatic or bactericidal against M tuberculosis, depending on the concentration of the drug attained at the site of infection. Its mechanism of action is unknown. Pyrazinamide is part of the triple-drug regimen.
Cross-section illustration of a testicle and epididymis. A: Caput or head of the epididymis. B: Corpus or body of the epididymis. C: Cauda or tail of the epididymis. D: Vas deferens. E: Testicle. Illustration by David Schumick, BS, CMI. Reprinted with the permission of the Cleveland Clinic Center for Medical Art and Photography © 2009. All Rights Reserved.
Cross-section illustration of a testicle and epididymis. A: Caput or head of the epididymis. B: Corpus or body of the epididymis. C: Cauda or tail of the epididymis. D: Vas deferens. E: Testicle. Illustration by David Schumick, BS, CMI. Reprinted with the permission of the Cleveland Clinic Center for Medical Art and Photography © 2009. All Rights Reserved.