The body is made up of many types of cells. Normally, cells grow and divide to produce more cells only when the body needs them. This orderly process helps keep the body healthy. Sometimes cells keep dividing when new cells are not needed. A mass of extra tissue forms, and this mass is called a growth or tumor.
Tumors can be benign or malignant.
Benign tumors are not cancer. They can usually be removed and, in most cases, they do not come back. Cells from benign tumors do not spread to other parts of the body. Fibroids are common benign tumors of the uterine muscle. These tumors do not develop into cancer.