When adult men take a bath, they might as well feel their scrotum with their hands and check their testicles, which is very important for timely detection of testicular tumors. When testicular tumor causes testicular enlargement, it usually does not feel too painful and sometimes only a cramping sensation. The swollen testicle becomes firm and loses its elasticity after a period of time. In the early stage, the surface of the testicle is smooth, but in the late stage, it becomes nodular and uneven, and soft and ulcerated by necrosis, which then connects with the scrotal skin, giving the scrotal surface a dark red color with twisted and dilated blood vessels. Since testicular tumors are highly malignant, insidious and easily metastasized, early detection is the key. When testicular enlargement is found by hand, one should go to the hospital in time to find out the cause and should not be careless. However, sometimes when examining the testicles by hand, a small swelling with a very smooth and well-defined surface is found in the scrotum, which feels like a sac filled with fluid. Some of them are very small, only a few millimeters in diameter; some are larger and look like an extra testicle. This is usually not a tumor, but a seminal cyst. If the fluid in the swelling is drawn out and looked at under a microscope, a large number of sperm can be found. The cause of seminal cysts is not known and can occur after pubertal development to older sperm. Men of any age before the termination of production. Most of them have no symptoms. It does not affect sexual life or fertility. Therefore, no treatment is required. If the cyst is large, or if there is localized discomfort of swelling, it can be surgically removed with good results.