Germ cell tumours can appear at any age in children. They can be either non-cancerous (benign) or cancerous (malignant).
During a normal pregnancy, as the foetus develops, the cells producing egg or sperm move to the ovaries or testes. However, occasionally these cells settle in other parts of the body and there they can develop into tumours.
The most common sites where germ cell tumours are found are in the area at the bottom of the spine (sacrococcygeal), the chest, brain and in the abdomen.The cause of germ cell tumours is unknown.