A spontaneous growth of tissue which forms an abnormal mass is called a tumor. A tumor that is noninvasive and noncancerous is referred to as a benign tumor.
Review Date 1/26/2017
Updated by: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.