Cancer: a group of diseases characterized by abnormal growth (neoplasm, tumor) and spread to other parts of the body (metastasism).
Osteosarcoma: A cancer of the bone that is most common in children. Also called osteogenic sarcoma.
Hodgkin's Disease: A malignant disease of the lymphatic system that is characterized by painless enlargement of lymph nodes, the spleen, or other lymphatic tissue. It is sometimes accompanied by symptoms such as fever, weight loss, fatigue, and night sweats.
Nephroblastoma: A fast-growing cancer of the kidneys that occurs most commonly in children under 4 years of age.