A spermatocele is a painless, fluid-filled cyst that develops in the epididymis, most commonly in the head (superior portion) near the top of the testicle. It contains dead sperm cells and clear or milky fluid. Spermatoceles are very common, especially in men over age 40, and are almost always benign. On ultrasound, a spermatocele appears as a well-defined, anechoic or hypoechoic cyst with posterior acoustic enhancement, located in the epididymal head and separate from the testis itself. Larger spermatoceles may contain internal echoes or septations. They are distinguished from other scrotal fluid collections such as hydrocele (which surrounds the testis) and epididymal cysts (which contain serous fluid rather than sperm). Treatment is typically unnecessary unless the spermatocele is large enough to cause discomfort.
Sonography Term