Testicular cancer is a disease in which cancer cells grow in one or both testicles. The testicles (or testes) are a pair of male sex glands that produce sperm and male hormones. They are located under the penis in a sac-like pouch called the scrotum. At the top of each testis is a bunch of tiny tubules that collect and store sperm. This structure is called the epididymis. The sperm travel from the epididymis through the spermatic cord (or vas deferens) and out through the urethra during ejaculation.

Male Genitalia

© 2009 Nucleus Medical Art, Inc.

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 can spread to other parts of the body. A benign tumor does not invade or spread.

Undescended testes (also called cryptorchidism) and testicular atrophy are associated with testicular cancer. The link between undescended testes and testicular cancer is high. Other risk factors, such as maternal estrogen use, testicular trauma, or infection have not clearly demonstrated a correlative relationship.

Normally the testes, which are inside the abdomen before birth, migrate into the scrotum by the time of birth. Occasionally though, boys are born with testes that are still in the abdomen or in the groin, not having completed their journey to the scrotum. This is called undescended testes. These testes are at high risk of cancer and should be moved into the scrotum or removed entirely as early as possible. Testicular atrophy describes testicles that are smaller than normal in size and occurs as a result of trauma or infection.

Testicular cancer is the most common form of cancer in young men between ages 20 and 35. The peak annual incidence ranges from 8 to 14 per 100,000 men between ages 20 and 35, with a smaller peak in early childhood. The incidence in black men is less than one-fifth that of white men.

Currently, over 90% of testicular cancers are cured.

What are the risk factors for testicular cancer?
What are the symptoms of testicular cancer?
How is testicular cancer diagnosed?
What are the treatments for testicular cancer?
Are there screening tests for testicular cancer?
How can I reduce my risk of testicular cancer?
What questions should I ask my healthcare provider?
What is it like to live with testicular cancer?
Where can I get more information about testicular cancer?