Testicular cancer is cancer that develops in the testicles, which are part of a man's reproductive system.

The testicles

The testicles are two small oval shaped organs which hang below the penis in a pouch of skin called the scrotum.

From the age of puberty the testicles produce sperm.

The collecting tubules inside the testicle join together to form a tube called the epididymis. This tube carries on and gets wider as it leaves the testicle. The wider tube is called the spermatic cord.

The spermatic cord forms a short tube called the ejaculatory duct. This duct opens into the urethra (the tube from the bladder to the end of the penis).

Testosterone

The testicles produce the hormone testosterone. Testosterone develops male qualities like:

• a deep voice
• beard growth
• muscle development
• the ability to have an erection
• male sex drive (libido)

Where testicular cancer starts

The testicles are made up of different types of cells. The type of cancer you have depends on the type of cell the cancer starts in.

Most testicular cancers develop in the cells that make sperm, called germ cells. The 2 main types of cancer that start in germ cells are:

• seminoma
• non seminoma (some doctors call these teratomas)

How common it is

Testicular cancer is rare.

In the UK around 2,400 men are diagnosed with testicular cancer each year. That's about 1 out of every 100 cancers (1%) diagnosed in men.

Who gets it

Younger men are more likely to get testicular cancer.

Men in their early 30s are the most likely to get it. It then becomes less common as men get older.