What is testicular cancer?

A central component to the male reproductive system is the testicles (or testes). These egg-shaped glands produce testosterone and sperm. Testosterone is a major male sexual hormone. Immature sperm are created by germ cells in the testicles; after, they move through tubes into the epididymis where the sperm mature and are stored. Mature sperm cells can fertilize female egg cells from the ovaries to begin a pregnancy.

Most testicular cancer forms within germ cells. This occurs when mutations in the germ cells grow abnormally and replicate, eventually forming a mass (or tumor) in the testicle.

Testicular cancer occurs more often in young and middle-aged males assigned at birth, and it is the most frequently diagnosed cancer in that population who are between 20 to 35 years old. More than 8,800 new cases of the cancer are diagnosed in the United States each year.

(Source: Cancer.gov)

Types of testicular cancer

There are two types of testicular germ cell cancers (with several subtypes). Germ cells develop into reproductive cells, and in males, they make sperm.

The frequency with which both types of testicular cancer can occur is nearly equal. In order to determine what type of cancer you may have, specially trained OSUCCC – James pathology experts analyze samples of testicular tumor cells to classify them.

Types of testicular cancer include:

Seminoma

Seminomas are most found in the testicles but can occur in other areas of the body such as the brain or chest. This type of testicular cancer often affects men in their 40s, but it can affect males of any age. Seminomas tend to grow more slowly but have a cure rate of more than 90%.

Seminomas can be further classified into subtypes:

• Anaplastic – This is a more aggressive type of testicular cancer and more likely to metastasize.
• Classical (typical) – This is the most common type of testicular cancer and accounts for about 85% of all seminomas.
• Spermatocytic – This type of testicular cancer usually occurs in men over 50 and accounts for less than 1% of all testicular cancer diagnoses. It is incredibly rare.

Nonseminomas

This type of testicular cancer also begins in the germ cells of men. Nonseminomas usually affects men in their mid- to late 30s; most have a cure rate of more than 95%.

Major types of nonseminomas include:

• Yolk sac carcinoma – This type of testicular cancer occurs often in pediatric cases but can be found in adults as well, most commonly in men in their 20s–30s.
• Choriocarcinoma – An incredibly aggressive and rare type of nonseminoma.
• Teratoma – Another type of aggressive testicular cancer that accounts for about 25% of all nonseminomas. Not all teratomas are malignant (cancerous).
• Embryonal carcinoma – Named for the way this cancer resembles a human embryo under a microscope, this type of cancer accounts for less than 4% of nonseminomas. It most often develops in younger men can also affect middle-aged men as well.

Stromal tumors

This type of testicular tumor grows in the tissue of the testicles. It is incredibly rare and makes up less than 4% of testicular tumors. These tumors can be further classified into two types: Leydig cell tumors and Sertoli cell tumors. Leydig cells are responsible for creating testosterone and Sertoli cells are essential to the production of sperm in males. Depending on where the tumor originates, it will help a pathologist classify the stromal tumor type.

In addition, cancer can spread to the testicles from another cancer in the body. When this happens, it's usually from a lymphoma, childhood leukemia, melanoma or cancer in a man’s prostate, kidney or lung are responsible for these secondary testicular cancers.

Related resources

Testicular Cancer Prevention 
Testicular Cancer Symptoms and Causes 
Testicular Cancer Screening and Diagnosis 
Testicular Cancer Treatment 
Testicular Cancer Treatment Team