Testicular cysts (usually epididymal cysts) are very common in middle-aged men. They usually have no obvious symptoms, occasionally a slight sensation of downward movement in the scrotum, and a unilateral enlargement and swelling of the scrotum if the cyst is significantly enlarged. Epididymal cysts are often caused by cystic changes in the epididymis, resulting in cyst formation. Most of them have no obvious clinical manifestations, but when the cyst increases in size, a round or round-like swelling with soft texture and clear boundaries will be felt in the testicles and epididymis, with a sense of fluctuation and no shrinkage by squeezing. Often, a dark area of fluid in this area can be detected by ultrasound. Epididymal cysts are often difficult to distinguish from syringomyelia, chronic epididymitis, and other diseases. Smaller epididymal cysts (less than 1㎝) do not require special treatment and should be reviewed every six months or once a year. Larger cysts can be located by ultrasound and then punctured to extract the fluid and injected with anhydrous alcohol or other sclerosing agents. If the cyst affects the function of the testicles or increases rapidly within a short period of time, the cyst can be removed surgically if it has a tendency to become cancerous. As mentioned above, the clinical symptoms of epididymal cysts are mainly a slight swelling in the perineum, and in severe cases, there may be local enlargement.