Cancer of the Testicle

Cancer of the Testicle Overview

Testicular cancer is an abnormal growth of cells in the testicles. The testicles are the male reproductive organs (gonads), where sperm are produced.

• The 2 small glands lie in a pouch of skin behind the penis called the scrotal sac, or scrotum.
• They are attached to the ejaculatory duct in the lower pelvis by cords called spermatic cords, which contain the vas deferens, the narrow tube through which the sperm moves out of the testis.
  
• Besides producing and storing sperm, the testicles (or testes) are the main source of male hormones such as testosterone, which control reproduction and sex drive (libido) and impart male physical traits such as deep voice and body and facial hair.
  
• Cancer usually occurs in only one testicle. Less than 5% of the time, it occurs in both testicles. (Usually, the 2 tumors are found at different times, the second perhaps years later.)

Cancer occurs when normal cells transform and begin to grow and multiply without normal controls.

• This uncontrolled growth results in a mass of abnormal cells called a tumor.
  
• Some tumors grow quickly, others more slowly. Almost all tumors start to cause symptoms when they get large enough.
  
• Tumors are dangerous because they overwhelm surrounding healthy tissue, taking not only its space but also the oxygen and nutrients it needs to carry out its normal functions.

Not all tumors are cancer. A tumor is considered cancer if it is malignant. This means that, if the tumor is not treated and stopped, it will spread to other parts of the body.

• Malignant tumors can spread to neighboring structures, usually lymph nodes. They encroach on and invade these healthy tissues, impairing their function and eventually destroying them.
  
• Tumor cells sometimes enter the bloodstream and spread to distant organs. There, they can grow as similar but separate tumors. This process is called metastasis.
  
• The most common places for testicular cancer to spread are the lungs and the lymph nodes in the area around your kidneys (the retroperitoneum), called the retroperitoneal lymph nodes. It also can spread to the lungs and liver.
  
• Metastatic cancers are the most difficult to cure.

Testicular cancers comprise several different types of tumor. The types are based on the cell type from which the tumor arises.

• By far the most common type is germ cell carcinoma. These tumors arise from the sperm forming cells within the testes.
  
• Other types of testicular tumors include Leydig cell tumors, Sertoli cell tumors, primitive neuroectodermal tumors (PNET), leiomyosarcomas, rhabdomyosarcomas, and mesotheliomas. None of these tumors is very common.
  
• Most of the information presented here concerns germ cell tumors.

There are 2 types of germ cells tumors, seminomas and nonseminomas (sometimes called teratomas).

• Seminomas arise from only one type of cell: immature germ cells that have not yet specialized. They are usually slow growing and tend not to spread from the testicle for a very long time. These constitute about 40% of all testicular cancers.
  
• Nonseminomas are composed of mature cells that have already specialized. Thus, these tumors often are "mixed," that is, they are made up of more than one tumor type. Typical components include choriocarcinoma, embryonal carcinoma, immature teratoma, and yolk sac tumor. These tumors tend to be faster growing and to spread more aggressively than seminomas.