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.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.