Neoplasia

Neoplasia literally means "new growth", and the new growth is neoplasm. Oncology (Greek oncos = tumor) is the study of tumors or neoplasm. Cancer is the common term for all maligant tumors.
Although all physisians know what they mean when they use the term neoplasm, it has been suprisingly difficult to develop an accurate definition. The eminent British oricologist Willis has come closest: "A neoplasm is an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persists in the same excessive manner after cessation of stimuli which evoked the change."