Print OverviewDesmoid 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.Products & ServicesA Book: Mayo Clinic Family Health Book, 5th EditionNewsletter: Mayo Clinic Health Letter — Digital EditionShow more products from Mayo Clinic SymptomsDesmoid tumor symptoms differ based on where the tumors occur. Desmoid tumors most often happen in the abdomen, arms and legs. But they can form anywhere in the body. In general, signs and symptoms include: A mass or area of swelling Pain Loss of function in the affected area Cramping and nausea, when desmoid tumors occur in the abdomen When to see a doctorMake an appointment with your doctor if you have any persistent signs or symptoms that worry you. Request an appointment CausesIt's not clear what causes desmoid tumors. Doctors know these tumors form when a connective tissue cell develops changes in its DNA. A cell's DNA contains the instructions that tell a cell what to do. The changes tell the connective tissue cell to multiply rapidly, creating a mass of cells (tumor) that can invade and destroy healthy body tissue. Risk factorsFactors that may increase the risk of desmoid tumors include: Young adult age. Desmoid tumors tend to occur in younger adults in their 20s and 30s. This tumor is rare in children and older people. A genetic syndrome that causes many colon polyps. People with familial adenomatous polyposis (FAP) have an increased risk of desmoid tumors. FAP is caused by a gene mutation that can be passed down from parents to children. It causes numerous growths (polyps) in the colon. Pregnancy. Rarely, a desmoid tumor may develop during or soon after pregnancy. Injury. A small number of desmoid tumors develop in people who've recently had an injury or surgery. By Mayo Clinic Staff Desmoid tumors care at Mayo Clinic Request an appointment Diagnosis & treatment Jan. 19, 2022 Print Living with desmoid tumors? Connect with others like you for support and answers to your questions in the Proton Beam Therapy support group on Mayo Clinic Connect, a patient community. Proton Beam Therapy Discussions Starting Proton Treatments for Prostate Cancer: Any experiences? 108 Replies Tue, Oct 03, 2023 chevron-right Meeting up with others who are having Proton Treatment 32 Replies Mon, Oct 02, 2023 chevron-right Anyone had Proton Beam Therapy for Meningioma? 13 Replies Sun, Sep 03, 2023 chevron-right See more discussions Show references Vinod R, et al. Desmoid tumors: Epidemiology, risk factors, molecular pathogenesis, clinical presentation, diagnosis and local therapy. https://www.uptodate.com/contents/search. Accessed Jan. 21, 2020. Gounder MM, et al. Locally aggressive connective tissue tumors. Journal of Clinical Oncology. 2018; doi:10.1200/JCO.2017.75.8482. Church J. Management of desmoid disease. Seminars in Colon and Rectal Surgery. 2018; doi:10.1053/j.scrs.2018.06.005. Soft tissue sarcoma. National Comprehensive Cancer Network. https://www.nccn.org/professionals/physician_gls/default.aspx. Accessed Jan. 21, 2020. Schmitz JJ, et al. Percutaneous cryoablation of extraabdominal desmoid tumors: A 10-year experience. American Journal of Roentgenology. 2016; doi:10.2214/AJR.15.14391. Related Products & Services A Book: Mayo Clinic Family Health Book, 5th Edition Newsletter: Mayo Clinic Health Letter — Digital Edition Show more products and services from Mayo Clinic Desmoid tumorsSymptoms&causesDiagnosis&treatmentDoctors&departmentsCare atMayoClinic Advertisement Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. Advertising & Sponsorship Policy Opportunities Ad Choices Mayo Clinic Press Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press. Mayo Clinic on Incontinence - Mayo Clinic PressMayo Clinic on IncontinenceThe Essential Diabetes Book - Mayo Clinic PressThe Essential Diabetes BookMayo Clinic on Hearing and Balance - Mayo Clinic PressMayo Clinic on Hearing and BalanceFREE Mayo Clinic Diet Assessment - Mayo Clinic PressFREE Mayo Clinic Diet AssessmentMayo Clinic Health Letter - FREE book - Mayo Clinic PressMayo Clinic Health Letter - FREE book CON-20213624 Patient Care & Health Information Diseases & Conditions Desmoid tumors