A desmoid tumor is an abnormal growth that arises from connective tissue, which is the tissue that provides strength and flexibility to structures such as bones, ligaments, and muscles. Typically, a single tumor develops, although some people have multiple tumors. The tumors can occur anywhere in the body.
Desmoid tumors are noncancerous growths that occur in the connective tissue. Desmoid tumors most often occur in the abdomen, arms and legs.
Another term for desmoid tumors is aggressive fibromatosis.
Some desmoid tumors are slow growing and don't require immediate treatment. Others grow quickly and are treated with surgery, radiation therapy, chemotherapy or other drugs.
Desmoid tumors aren't considered cancers because they don't spread to other areas of the body. But they can be very aggressive, acting more like cancers and growing into nearby structures and organs. For this reason, people with desmoid tumors are often cared for by cancer doctors.