Spermatocele is a retention cyst of a tubule of the rete testis or the head of the epididymis. The cyst is distended with a milky fluid that contains sperm.

Located at the superior pole of the testis and caput epididymis, the spermatocele is soft and fluctuant and can be transilluminated (a flashlight can be seen if shined through the scrotal mass).


Spermatoceles are epididymal cysts so named because of the frequent finding of sperm in the cyst fluid. They are the most common cystic condition encountered within the scrotum.

Spermatoceles are usually found at the head of the epididymis, adjacent or posterior to the superior pole of the testicle.

Spermatoceles vary in size from several millimeters to many centimeters in diameter and may be single or multiple, unilateral or bilateral.


The cause of spermatoceles remains controversial. It is believed that they may originate as a diverticulum from the tubules found in the head of the epididymis. With spermatogenesis over time, the diverticulum increases in size, ultimately producing a spermatocele.

Spermatoceles also are believed to form as a result of infection (epididymitis) or trauma. If any portion of the epididymis becomes obstructed by scar formation, a spermatocele can form.


Spermatoceles typically present as incidental scrotal masses found on routine physical examination. They may be discovered by an individual during self-inspection of his scrotum or testicles, or when large, by palpation by his partner.

Spermatoceles are asymptomatic except when large, and then may be associated with testicular discomfort.


The differential diagnosis of a painless scrotal mass includes spermatocele, hydrocele, hernia, varicocele, tuberculosis of the epididymis, and tumors of the testicle or epididymis.

Acute inflammatory processes involving the epididymis or testicle such as epididymitis, orchitis, or testicular torsion, are associated with a high degree of pain and should not be confused with spermatocele.

Diagnosis of spermatocele is best made on physical examination. The finding of a cystic, painless mass at the head of the epididymis that transilluminates and can be definitely differentiated from the testicle is generally sufficient to confirm the diagnosis.

If uncertainty exists, ultrasonography of the scrotum will confirm the diagnosis.


Small cysts of the epididymis are best left alone, as are larger cysts when asymptomatic. Only when the cysts are associated with discomfort and are enlarging in size, or when the patient wants the spermatocele removed, should surgical intervention be considered.

The patient should be made aware that spermatocelectomy will not improve fertility and should not be performed for this reason. It also is possible that pain may persist after spermatocele removal.

Once it has been decided to proceed with spermatocelectomy, the procedure can be performed on an outpatient basis. The technique is performed easily under local or general anesthesia.