Osteosarcoma is a malignant type of bone tumour. It is more common in older children and teenagers. Osteosarcoma usually starts to develop at the end of the long bones, which is where new bone tissue is formed when the child grows. The most common sites for osteosarcoma are arms and legs.
Ewing sarcoma is another type of bone cancer that is usually formed in the long bones, ribs, pelvis and spine. Ewing sarcoma can, in some cases, also occur in the soft tissues.
Rhabdomyosarcoma is a cancer of the soft tissue, more specifically of the muscle tissue. It can basically develop anywhere in the body, but is most frequently found in the head and neck, bladder, testes, uterus or vagina.
Neuroblastoma is a cancer that develops from primitive cells that are left behind from prenatal development (neuroblasts). Neuroblastoma is the most common cancer in babies and the third-most common cancer in children after leukaemia and brain tumours. Neuroblastoma can develop anywhere in the body, but originates from one of the two adrenal glands or from nerve tissue alongside the spinal cord.
Wilms’ tumour is the most frequently encountered cancer of the kidney in children. It is thought to develop from immature cells in the embryo (normally these cells disappear at birth).
Germ cell tumours
Germ cell tumours develop from the germ cells, which are the precursor of the reproductive cells (oocyte or sperm). During prenatal development of the foetus, the germ cells producing eggs or sperm normally move to the ovaries or testes. The tumour usually develops in the reproductive system (ovaries or testes) but it can also develop in the brain or another part of the body. Germ cell tumours are sometimes given different names based on what they look like under the microscope. These include yolk-sac tumours, germinomas, embryonal carcinomas, mature teratomas and immature teratomas.
They may be non-cancerous (benign) or cancerous (malignant). Malignant tumours have the ability to grow and spread to other parts of the body.
Immature teratomas fall between benign and malignant tumours. They can occur at many different sites (most commonly in the abdomen)and can spread locally, such as within the abdomen, but rarely beyond. They can usually be surgically removed.
Retinoblastoma is a cancer type of the eye and can occur in the context of a genetic abnormality that predisposes to the development of retinoblastoma (usually young children and bilateral tumours -in both eyes) or sporadically (usually unilateral retinoblastoma – in one eye).
There are 2 types of malignant liver tumours that occur in children
- Hepatoblastoma: occurs usually in children younger than 5 years old
- Hepatocellular carcinoma: is very rare and occurs in older children or in children with a diseased liver