Testicular tumor is one of the most common tumors in young adults aged 20 to 35 years. It occasionally occurs in infants and the elderly. It accounts for 1% to 2% of all malignant tumors in men and 3% to 9% of genitourinary tumors in men. It has the highest incidence in Scandinavia, Switzerland, Germany and New Zealand, followed by the United Kingdom and the United States, and the lowest in Africa and Asia. Risk factors 1. Cryptorchidism: 7%~10% of patients have a history of cryptorchidism. The causes of cryptorchidism leading to malignant transformation may be related to local temperature increase, blood supply disorder, endocrine disorder and gonadal dysplasia. The incidence of testicular tumor in patients with cryptorchidism is 9~14 times higher than that of normal population. About 1/5 patients with history of cryptorchidism can have tumor in the normal testis on the opposite side or the tumor only occurs in the normal side. 2. Testicular dysplasia or congenital defects: exogenous estrogen during pregnancy may lead to abnormal testicular descent or dysplasia of the fetus, which is a risk factor for the occurrence of testicular tumor. 3. Testicular trauma and infection: the period of active endocrine action is a factor that induces testicular tumor. 4.Heredity may also be a factor of testicular tumor development. 5. Viral infections such as measles, smallpox, mumps and certain bacterial infections such as scarlet fever, typhoid fever, etc. can complicate acute orchitis, followed by testicular atrophy and intercellular degeneration and testicular tumor. Abnormal manifestation 1.Nodules appear in the testes, and the texture becomes hard. 2. Testicular enlargement: about 88% of patients may have testicles gradually enlarged, with smooth or bumpy surface, and the enlarged testicles are hard like stones. Some patients may have normal or slightly larger testicles, with only a feeling of testicular heaviness and dropping, and the symptoms are aggravated after running, jumping, standing for a long time or exertion, or slight pain, which is aggravated when encountering collision or extrusion. 3.Pain: 90% of patients have lost testicular sensation and no pain. When bleeding and necrosis occur within the tumor, it can make the testis enlarge rapidly and cause acute pain in the testis, similar to acute inflammatory testicular torsion entrapment, and although the inflammation is controlled after anti-sensory treatment, the mass does not disappear. 4.Acute abdominal pain: caused by bleeding of cryptorchid tumor in abdominal cavity or rupture of metastatic foci. 5.Patients with cryptorchidism, when the ectopic testis becomes malignant, a gradually enlarged mass often appears in the inguinal region in the pelvis. 6.About 5% of patients have feminization of breast, and very few patients have infertility as the main complaint. 7. Metastatic symptoms are mainly lymph node metastasis, commonly in the groin, internal iliac artery, common iliac artery, abdominal aorta and mediastinum. A mass can be palpated in the abdomen, and patients complain of low back pain; lung metastases may present with cough, hemoptysis or dyspnea; retroperitoneal metastases may present with lack of appetite, gastrointestinal bleeding, etc. About 10% of patients mainly present with metastatic symptoms, and intra-testicular signs are only found later. III. Danger signs 1. Heavy sensation and no pressure pain in the testes, and loss of sensitivity in the normal state. 2.Lumps in the scrotum and in the groin. 3.The testicles are enlarged, inelastic and without pressure pain. 4.The original atrophied testicles gradually increase in size, should be highly alert. Preventive health care 1.Early treatment of cryptorchidism in children has positive significance to prevent testicular tumor. 1 year old before the testicle has a better chance of natural descent, so it is advisable to do cryptorchidism fixation surgery for children with cryptorchidism at the age of 1~2 years. 2. Testicular tumors can still occur in patients who have undergone cryptorchidism fixation after many years, therefore, such patients should pay attention to checking testicles frequently and provide timely treatment when abnormalities occur. 3.Atrophied testicles should be removed no matter where they are located, and pay attention to self-examination. 4.Once the testicle is found to be enlarged and has the tendency of malignant transformation, early surgery is recommended. 5.Pay attention to the protection of the testicles and avoid trauma. 6, timely treatment of testicular inflammation. 7. Patients with testicular tumor should insist on self-examination of testicles after treatment and regular follow up prevention for at least 3 years. If there is no recurrence within 3 years and very little chance of recurrence in the future, the review time can be extended appropriately. V. Signals of recurrence of testicular tumor Before treatment, urine HCG is positive or alpha-fetoprotein is positive, but after treatment, it is normal again, if it appears positive again, there is a possibility of recurrence, and patients should consult a doctor in time.