What is Testicular Cancer?

Testicular cancer is a disease in which cancer cells form in the tissues of one or both testicles. According to the National Cancer Institute, testicular cancer is very rare and is most frequently diagnosed in men ages 20 to 34.

Types of Testicular Cancer

There are two main types of testicular cancer: germ cell tumors and stromal tumors. In addition, both types have subtypes.

Germ Cell Tumors

Germ cell tumors are the most common type of testicular cancer, accounting for over 90 percent of testicular cancer. There are two main types of germ cell tumors, and males can have one type or a mixed type.

• Seminoma germ cell tumors – Categorized by slow growth and spread in most cases. Sub-type seminoma can be classified as:
  • Classic seminoma – Accounts for 95 percent of seminoma germ cell tumors.
  • Spermatocytic seminoma – More common in older men.
• Nonseminomatous germ cell tumors – The second type of germ cell tumor and can vary in their appearance and prognosis. There are four subtypes, but most people will have a mixture of two or more types:
  • Embryonal carcinoma – A rapidly growing and aggressive tumor, which occurs in about 40 percent of nonseminomatous germ cell tumors.
  • Yolk sac carcinoma – The most common type of testicular tumor in children, but it's rare in adults.
  • Choriocarcinoma – A very rare and aggressive type of tumor.
  • Teratoma – Usually occurs in the mixed type of tumor. It is usually local but may spread to nearby lymph nodes.

Stromal Tumors

Stromal tumors make up less than 5 percent of testicular cancers. They develop in tissues around the germ (reproductive) cells in testicles. There are two types of stromal tumors:

• Leydig cell tumors – They make testosterone.
• Sertoli cell tumors – They are usually benign.

Signs & Symptoms

Some men may not have symptoms of testicular cancer, even if the cancer starts to spread. If there are symptoms, they may include:

• A lump in the testicle
• Testicle swelling
• A heavy feeling in the scrotum or lower abdomen
• Aching in the scrotum or lower abdomen
• Pain in the scrotum
• Infertility

Risk Factors & Prevention

Scientists have found few risk factors that make someone more likely to develop testicular cancer. Risk factors for testicular cancer may include:

• An undescended testicle
• Family history of testicular cancer
• HIV infection
• Carcinoma in situ of the testicle
• Having had testicular cancer before
• Being of a certain race/ethnicity
• Body size

There is no standard or routine screening test used for the early detection of testicular cancer. Most often, testicular cancer is first found by men themselves, either by chance or during self-exam. Sometimes the cancer is found by a physician during a routine physical exam.