Neoplasm is an abnormal growth of tissue, which if it forms a mass, is commonly referred to as a tumor. This abnormal growth (neoplasia) usually but not always forms a mass.
ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology.
Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia.However, metaplasia or dysplasia does not always progress to neoplasia The word is from Ancient Greek νέος- neo “new” and πλάσμα plasma “formation, creation”.