Spermatoceles. A spermatocele is a benign cyst consisting of nonviable sperm. They are commonly located in the head of the epididymis, but have been found in the body and tail as well. Septations have been seen with the cysts. The spermatoceles may be singular or multiple
On sonography, a spermatocele appears as a cyst, anechoic with posterior enhancement with rounded, well-defined walls. A spermatocele cannot be differentiated from a simple epididymal cyst.
Epididymal Cysts. These masses are composed of clear serous fluid, not sperm and are much less common than spermatoceles. Sonographically they present as a typical cystic type appearance with well-defined walls and good transmission.

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