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.
Germ cells within the testicles produce immature sperm that travel through a network of tubules and larger tubes into the epididymis, where the sperm mature and are stored. Almost all testicular cancers start in these germ cells.
There are two kinds of germ cell tumors: seminomas and nonseminomas. These two types grow and spread differently, and are treated differently.
Seminomas begin in immature germ cells, the cells that would normally become sperm. Seminomas are slow-growing tumors and are the most common testicular tumor found in men in their 30s and 40s. Seminomas are very sensitive to radiation therapy.
Nonseminomas are more common in infants and children, and tend to grow more quickly than seminomas. These tumors are further classified by the type of cell in which they begin. The four subtypes of nonseminomas include:
- Embryonal carcinoma
- Yolk sac carcinoma, and
Most testicular cancers are considered very treatable, and there is a high survival rate for men who develop these conditions.