A germ cell is a special type of cell that forms during the fetal development. The germ cells in later stages developed into sperm in the testicles or eggs in the ovaries. But sometimes these germ cells develop outside the gonads called as extragonadal cells and may convert into a germ cell tumor in those of the body termed as extragonadal germ cell tumor. This mishap may occur either before or after birth.
This tumor may begin to grow in any part of the body, but mostly it happens in the pineal gland inside the brain, the chest, the lower part of the spine, or the abdomen. Severe pain and lump appearance in the affected area can help to guess about this tumor.