Testicular cancer is a disease in which cancer cells grow in one or both testicles. The testicles are a pair of male sex glands that make and store sperm. The testicles also make male hormones. They are located under the penis in a sac-like pouch called the scrotum.

There are three main types of testicular cancer:

  • Seminomas
  • Nonseminomas (yolk sac, embryonal cell carcinoma, teratomas, and choriocarcinoma)
  • Stromal cell tumors

Treatment will vary depending on the cell type.

Cancer occurs when cells in the body (in this case testicular cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissues and spread to other parts of the body. A benign tumor does not invade or spread.

The causes of testicular cancer are unknown. However, research shows that certain risk factors are associated with the disease.