An extragonadal germ cell tumor is a type of tumor that develops from egg cells or sperm cells that are developing that travel to other parts of the body from the gonads. These tumors can start forming in any part of the body, but most often begin in the pineal gland or abdomen. These tumors can be cancerous or noncancerous, and noncancerous ones are more common. Only if it is cancerous is it termed either seminoma or nonseminoma. Extragonadal germ cell tumor symptoms almost always occur when the tumor is cancerous.
As the tumor grows, symptoms may begin to occur. These may include:
- Breathing problems
- Change in bowel habits
- Trouble walking
- Chest pain
- Feeling very tired
- Trouble moving the eyes or seeing
In addition to extragonadal germ cell tumor symptoms, complications may also occur. Teratoma with malignant transformation may occur, but is a rare complication. The most common transformations include glioblastomas, neuroblastomas, hematologic malignancies, sarcomas, nephroblastomas, and adenocarcinomas. Other possible complications may include:
- Isolated thrombocytopenia
- Systemic mastocytosis
Statistics and Prognosis
This type of tumor accounts for about five to ten percent of all germ cell tumors in the United States. The five-year survival rate is 40 to 65 percent for those receiving intensive chemotherapy. The best survival rates are with extragonadal seminomas. 30 to 40 percent of these tumors are seminomas, while nomseminomatous tumors account for 60 to 70 percent. These tumors occur most often in the mediastinum, accounting for 50 to 70 percent of these tumors, followed by 30 to 40 percent in the retroperitoneum, five percent in the pineal gland, and less than five percent in the sacrococcygeal area.
These tumors occur equally among both genders in children. In adults, only the noncancerous form occurs equally among both genders. 90 percent of the cancerous tumors in adults affect males. Overall, young males are most commonly affected.
When noncancerous tumors occur outside of the brain, they rarely threaten survival. When the tumors are cancerous, the location heavily determines survival. Seminomas in the mediastinum have about an 80 percent long-term survival rate in patients treated only with radiation. Some studies have shown that when chemotherapy is added, survival rates increase. Nonseminomas in this location have about a 50 percent survival rate after chemotherapy, specifically when this tumor has yet to invade the surrounding lung areas in the chest’s central portion.
In the presacral area, survival rates are only about 28 percent, even when the cancer is localized. Once it has spread to other organs, the survival rate is about four percent.
In the pineal area, survival rates are about 80 percent for long-term survival once the patient has gone through treatment.
WebMD. (2010). Extragonadal Germ Cell Tumors Treatment – General Information About Extragonadal Germ Cell Tumors: https://www.webmd.com/cancer/tc/extragonadal-germ-cell-tumors-treatment-patient-information-nci-pdq-general-information-about
Aetna InteliHealth. (2007). Extragonadal Germ Cell Tumors. Retrieved on September 12, 2010 from Aetna InteliHealth: https://www.intelihealth.com/IH/ihtIH/E/9339/24580.html
Sachdeva, K. MD, et al. (2008). Extragonadal Germ Cell Tumors. Retrieved on September 12, 2010 from eMedicine Medscape: https://emedicine.medscape.com/article/278174-overview