When adult men take a bath, they might as well feel the scrotum with their hands and check the testicles, which is of great significance for timely detection of testicular tumor. When testicular tumor causes enlarged testicles, you usually don’t feel too much pain, and sometimes you only have a feeling of swelling. The enlarged testicle becomes firm and loses elasticity after a period of time. In the early stage, the surface of testis is smooth, but in the late stage, it is nodular and uneven, and softened and ulcerated by necrosis, which in turn connects with the skin of scrotum, giving the surface of scrotum a dark red color and accompanied by twisted and dilated blood vessels. Due to the high degree of malignancy of testicular tumor, the development of the disease is hidden and easy to metastasize, so early detection is the key. When testicular tumor is found to be enlarged by touching with hands, one should go to the hospital in time to find out the cause and should not be careless. However, sometimes when checking the testicles by hand, a small swelling with a very smooth surface and clear boundaries will be found in the scrotum, which is molded with a fluid-filled sac-like feeling. Some are very small, only a few millimeters in diameter; some are larger, like an extra testicle. This is usually not a tumor, but a semen cyst. If the fluid in the swelling is drawn out and looked at under a microscope, a large number of spermatozoa can be found. The cause of seminal cysts is unknown and can occur in men of any age from puberty through old age. Most of them do not have any symptoms. It does not affect sex life or fertility. Therefore, no treatment is needed. If the cyst is large, or there is localized swelling and discomfort, it can be surgically removed with good results.