Benign growths by definition are not cancerous. So, what is cancerous? Cancerous means that the mass or tumor is growing without control and invading nearby tissues or structures. When this growth moves from one part of the body to another, it is known as metastasizing.
So what is it when the tissue grows, but does not invade nearby tissues or structures? A benign tumor. Another way to think of benign tumors is as an overgrowth of tissue or cells. Some of these growths may change from benign to precancerous lesions, which means that they may develop into cancer in the future.
The most common types of benign tumors are:
- Adenomas. These arise from epithelial cells lining a gland or gland-like structure. An example of an adenoma is a polyp in the colon
- Fibromas. These start from fibrous or connective tissue
- Hemangiomas. These benign tumors form from cells that usually comprise blood vessels. Hemangiomas are a common form of a birthmark.
- Lipomas. These benign tumors start from fat cells and are extremely common.
Benign tumors are usually simply followed by close observation or monitoring by a physician. Unless these growths change from benign to precancerous or cancerous or cause symptoms, treatment is usually not required.