What is a Benign Tumor?

A tumor of favorable outlook. A benign tumor is a local growth, from an increase in the number of cells, which has no tendency to invade adjacent tissues or to seed out to remote parts of the body. Benign tumors are commonly enclosed in a definite capsule. They can, however, cause trouble by local pressure effects, especially in confined spaces such as the inside of the skull.

This benign tumor of the submandibular gland, also known as pleomorphic adenoma, presented as a painless neck mass in a 40-year-old man. At the left of the image is the white tumor with its characteristic cartilaginous cut surface. To the right is the normally lobated submandibular salivary gland.