Testicular Cancer Types

Tumors that occur in the testicles may be caused by different types of cancer. Some tumors are slow-growing, while others, such as choriocarcinoma, grow quickly and aggressively. While many types of testicle cancer affect adults, some are much more common in children.

Germ Cell Tumors

Almost ninety percent of all testicular cancers are germ cell tumors. Germ cell tumors develop in the testicle’s sperm-producing cells, known medically as germ cells. Germ cell tumors are divided into two groups, seminoma and non-seminoma tumors, depending on how they appear microscopically. Testicular cancer may be a combination of seminoma and non-seminoma cancers, in which case the tumors are referred to as mixed germ cell tumors.

Types of Seminoma Tumors

Seminoma cancers are the most common type of germ cell tumors, accounting for forty percent of all germ cell tumor diagnoses. Seminoma testicular cancer is malignant and usually affects men in their thirties. Seminoma tumors are often painless. One testicle may become enlarged as the cancer develops.

Choriocarcinoma and Other Types of Non-seminoma Testicular Cancer

Non-seminoma testicular cancer is separated into four types: choriocarcinoma, embryonal carcinoma, endodermal sinus tumors, and teratoma tumors. Non-seminoma testicular cancer is the most common cancer of the testicles in young children.

Choriocarcinoma: Choriocarcinoma is one of the rarest germ cell tumors. Choriocarcinoma tumors are malignant and one of the most aggressive types of testicular cancer. Young men and children between the ages of ten and thirty are most at risk for choriocarcinoma.

Embryonal Carcinoma: Embryonal carcinoma tumors are the most common type of testicular cancer in children. Tumors are malignant and grow rapidly. Children often experience pain in the affected testicle, and the cancer may metastasize to distant organs.

Endodermal Sinus Tumors: Endodermal sinus tumors are also referred to as yolk sac tumors. A malignant tumor, this type of testicular cancer usually affects children, including very young infants.

Teratoma: Teratoma tumors are usually malignant. The testicle tumors are composed of different types of tissue, such as muscle or cartilage.

Stromal Sex-Cord Tumors

Stromal sex-cord tumors are rarer types of cancer than germ cell tumors, comprising only four percent of adult testicular cancers. Stromal sex-cord tumors are more common in children, and represent twenty percent of all pediatric testicular cancer. There are two main types:

Leydig Cell Tumors: Leydig cell tumors are often benign. The tumors produce sex hormones, which may cause early puberty in children. Adults may experience gynecomastia, or breast tissue growth.

Sertoli Cell Tumors: Typically benign, sertoli cell tumors resemble leydig cell tumors without producing sex hormones.

Secondary Types of Testicle Tumors

In addition to primary types of cancer, a number of secondary cancers may spread to the testicles. Such cancers include:


American Cancer Society. (updated 2003). What is testicular cancer? Retrieved November 4, 2003, from www.cancer.org/docroot/cri/content/cri_2_4_1x_what_is_testicular_cancer_ 41.asp?sitearea=cri.

Kinkade, S. (1999). Testicular cancer. Retrieved November 4, 2003, from www.aafp.org/afp/990501ap/2539.html.