Testicular cancer occurs when abnormal cells in the testicles divide and grow in an uncontrolled manner. Testicular cancer can develop in one or both testicles and occurs in men or young boys.
The testicles have several different types of cells. The different cells can develop into one or more types of cancer. The three main types of testicular cancer include germ cell tumors, stromal tumors and secondary testicular tumors.
Germ cell tumors are the most common type of testicular cancer. Germ cell tumors grow in the cells that produce sperm. There are two kinds of germ cell tumors: seminomas and nonseminomas.
Seminomas consist of immature germ cells, the cells that would normally become sperm. Seminomas are slow growing tumors that tend to remain in the testicle for a long period of time. Most seminomas are found in men between their late 30s and early 50s.
Nonseminomas are classified by the type of cell in which they begin. There are four subtypes of nonseminomas including embryonal carcinoma, teratoma, choriocarcinoma, and yolk sac carcinoma. These types of testicular cancers tend to occur in men in their late teens to early 40s.
Stromal tumors are different from germ cell cancers because they grow in other parts of the testicles, such as the cells that produce hormones.
Secondary testicular tumors are caused by cancer that has spread to the testicles from other parts of the body.
Most testicular cancers are considered very treatable, and there is a high survival rate for men who develop this condition.