What Are Germ Cell Tumors?

Germ cell tumors (GCTs) are a rare type of cancer that starts in the cells that give rise to sperm or eggs. These cells are called germ cells. GCTs can occur in both men and women.

GCTs can occur in many parts of the body, including:

- Testicles

- Ovaries

- Brain

- Lungs

- Liver

- Mediastinum (the area between the lungs)

- Neck

- Retroperitoneum (the area behind the peritoneum, which is the membrane that lines the abdominal cavity)

GCTs are classified according to their cell type and their location in the body. Some of the most common types of GCTs include:

- Seminomas are the most common type of GCT in men. They usually occur in the testicles.

- Nonseminomas are a type of GCT that is less common than seminomas. They can occur in the testicles, ovaries, or other parts of the body.

- Dysgerminomas are a type of GCT that occurs in women. They usually occur in the ovaries.

- Mixed germ cell tumors contain both seminoma and nonseminoma cells.

- Yolk sac tumors: germ cell tumors that usually develop in the gonads of fetuses. However, they can also develop in adults, often in association with other types of germ cell tumors.

GCTs are relatively rare, but they are the most common type of cancer in adolescents and young adults. The exact cause of GCTs is unknown, but certain risk factors may increase a person's chance of developing these cancers, such as:

- Family history of GCTs

- Undescended testicles

- Infertility

- Certain genetic disorders

GCTs are curable if they are found and treated early. Treatment for GCTs may include surgery, chemotherapy, radiation therapy, and stem cell transplant.