Yolk Sac or Germ Cell Tumor

A yolk sac tumor is a rare, malignant tumor of cells that line the yolk sac of the embryo.

These cells normally become ovaries or testes; however, the tumor can also occur in areas such as the brain or chest.

The cause of a yolk sac tumor is unknown. It is most often found in children before the ages of 1 to 2.

Yolk sac tumors are also known as germ cell tumors, teratomas, or embryonal carcinoma.

These tumors are usually found in the ovary, testes, or the sacrococcygeal area (at the bottom of the spine).

Within the testes, the tumor is a visible, painless, firm swelling.

In the ovary it is not as visible and the tumor may grow very large before being noticed.

In the sacrococcygeal area, it may be seen as a swelling of the buttocks often mistaken for a bruise or infection.

These cancer cells secrete specific hormones, two of which are alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG).

A blood test which shows an increase in either of these can help with the diagnosis. Other studies may include an ultrasound, CT scan, or MRI of the pelvis and a biopsy of the suspicious mass. The biopsy is done in surgery under general anesthesia so the child is not conscious and will not feel any pain.

Germ cell tumors can be diagnosed in utero.

Sacrococcygeal teratomas are the most common germ cell tumor of childhood and the most frequently recognized neoplasm of the fetus.

The staging depends on whether the tumor is in only one place or if it has spread to other parts of the body.

Treatment decisions are made depending on the stage and location of the tumor.

Surgery is the most effective treatment, if the tumor is in one location.

If the tumor is in the testes, surgery is done before chemotherapy.

If the tumor is in the ovaries or sacrococcygeal region, chemotherapy is usually given first to shrink the tumor. Then surgery is performed. Radiation is used less often and can be done as an inpatient or an outpatient. 

Prognosis for germ cell tumors varies greatly depending on multiple factors, including child's age, tumor location, and staging.

For additional information on this topic, contact us at cancer@cchmc.org.

Last Updated 03/2016