cancer: a malignant neoplasm

neoplasm: a blanket term referring to an uncontrolled growth of abnormal cells in either humans or animals. Neoplasms may be benign (do not invade surrounding tissues or spread to other parts of the body) or malignant (invade surrounding tissues and spread to new sites in other parts of the body)

tumour: a neoplasm that forms an abnormal solid mass of tissue (in contrast to neoplasms such as leukaemia, which do not form tumours). Tumours can be benign or malignant