The testicles, or testes, are the male sex glands that produce sperm. Testicular cancer or cancer of the testes occurs when cancer cells form in one or both testicles. Reproductive cells called germ cells develop into sperm through a process of cellular division called meiosis. Sometimes the germ cells begin to divide uncontrollably and, instead of producing functional sperm. When this happens, the cells are considered cancerous.
Most often testicular cancer is detected as a painless lump in one of the testicles. Testicular cancer is highly treatable and one of the most curable forms of cancer. It is especially important to detect testicular cancer in the earliest stages where the cure rate is almost 100%. That is why self-exams, starting in the adolescent years, are key in early detection of testicular cancer.