What is a Spermatocele?
A spermatocele is a benign, fluid-filled cystic dilation of the epididymis that contains spermatozoa, typically arising from the head of the epididymis and presenting as a painless scrotal mass. 1, 2
Clinical Characteristics
Spermatoceles are benign lesions that develop as cystic dilations within the epididymal tubules, most commonly at the head of the epididymis 1, 3
The cysts contain fluid with spermatozoa, which distinguishes them from simple epididymal cysts 3, 4
Most spermatoceles remain asymptomatic and are discovered incidentally during routine physical examination or scrotal ultrasound 3
They typically present as smooth, separate masses above and behind the testis that transilluminate on physical examination 3
When Patients Seek Treatment
Men tolerate spermatoceles for an average of 48 months before seeking intervention 1
Patients typically seek treatment when the spermatocele grows to approximately 4.2 cm in diameter—roughly the size of a normal testicle 1
The most common presenting symptoms are a combination of pain and sensation of mass (58% of cases), rather than pain alone 1
Men who experience pain as an isolated symptom tend to be approximately 10 years younger than those bothered primarily by the mass effect 1
Right-sided spermatoceles are more common (71%) than left-sided lesions 1
Important Clinical Considerations
While most spermatoceles are unilocular, multilocular variants can occur and may arise from the rete testis, occasionally simulating solid tumors on examination 4
Giant spermatoceles can mimic hydroceles clinically due to their transilluminating appearance, making ultrasound evaluation important for accurate diagnosis 3
Aspiration is not recommended as a definitive treatment, as spermatoceles invariably recur after aspiration and may become even larger 2
Torsion of a spermatocele is extremely rare but should be considered in the differential diagnosis of acute scrotum, though it cannot be reliably distinguished from testicular torsion without surgical exploration 5