Testicular cancer forms in the testicles, the male reproductive glands located in the scrotum. Testicular cancer is treated successfully in more than 95% of cases.
Most commonly, testicular cancer starts in cells that produce sperm. These tumors, called germ cell tumors (GCTs), are most common in men between 20 and 40 years of age. There are two main types of germ cell tumors: seminomas and nonseminomas.