Childhood extracranial germ cell tumors form from developing sperm or egg cells that travel to parts of the body other than the brain.
As a fetus develops, certain cells form sperm in the testicles or eggs in the ovaries. Sometimes these cells travel to other parts of the body and grow into germ cell tumors. This summary is about germ cell tumors that form in parts of the body that are extracranial (outside the brain). Extracranial germ cell tumors are most common in teenagers 15 to 19 years old.
Many of the medical and scientific terms used in this summary are found in the NCI Dictionary of Genetics Terms. When a linked term is clicked, the definition will appear in a separate window.
Many of the genes described in this summary are found in the Online Mendelian Inheritance in Man (OMIM) database. When OMIM appears after a gene name or the name of a condition, click on OMIM for a link to more information.
There are several hereditary syndromes that involve endocrine or neuroendocrine glands,...
Childhood extracranial germ cell tumors are grouped as gonadal or extragonadal.
Malignant extracranial germ cell tumors are grouped into gonadal and extragonadal.
Gonadal Germ Cell Tumors
Gonadal germ cell tumors form in the testicles or ovaries.
Testicular Germ Cell Tumors
Testicular germ cell tumors usually occur before the age of 4 years or in teenagers and young adults.
Testicular germ cell tumors in teenagers and young adults are different from those that form in early childhood. They are more like testicular cancer in adults. Testicular germ cell tumors are divided into two main types, seminoma and nonseminoma. (See the PDQ summary on Testicular Cancer Treatment for more information.)
Seminoma: These tumors make a hormone called beta-human chorionic gonadotropin (β-hCG).
Nonseminoma: These tumors are usually large and cause symptoms. They tend to grow and spread more quickly than seminomas.