Tumor

特許 権利維持 Neoplasm (from Ancient Greek νέος- neo "new" and πλάσμα plasma "formation, creation") is an abnormal growth of tissue, and when also forming a mass is commonly referred to as a tumor or tumour.[1][2] This abnormal growth (neoplasia) usually but not always forms a mass.[3] The World Health Organization (WHO) classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior.