Signs and symptoms of sarcoma include:  A lump that can be felt through the skin that may or may not be painful Bone pain A broken bone that happens unexpectedly, such as with a minor injury or no injury at all Abdominal pain Weight loss  Causes It's not clear what causes most sarcomas. In general, cancer forms when changes (mutations) happen in the DNA within cells. The DNA inside a cell is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform, as well as how to grow and divide. Mutations might tell cells to grow and divide uncontrollably and to continue living when normal cells would die. If this happens, the accumulating abnormal cells can form a tumor. Cells can break away and spread (metastasize) to other parts of the body. Risk factors Factors that can increase the risk of sarcoma include:  Inherited syndromes. Some syndromes that increase the risk of cancer can be passed from parents to children. Examples of syndromes that increase the risk of sarcoma include familial retinoblastoma and neurofibromatosis type 1. Radiation therapy for cancer. Radiation treatment for cancer increases the risk of developing a sarcoma later. Chronic swelling (lymphedema). Lymphedema is swelling caused by a backup of lymph fluid that occurs when the lymphatic system is blocked or damaged. It increases the risk of a type of sarcoma called angiosarcoma. Exposure to chemicals. Certain chemicals, such as some industrial chemicals and herbicides, can increase the risk of sarcoma that affects the liver. Exposure to viruses. The virus called human herpesvirus 8 can increase the risk of a type of sarcoma called Kaposi's sarcoma in people with weakened immune systems.                   By Mayo Clinic Staff By Mayo Clinic Staff  Sarcoma care at Mayo Clinic 
signs symptoms sarcoma include:  lump can felt skin may may painful bone pain broken bone happens unexpectedly  minor injury injury abdominal pain weight loss  causes it's clear causes sarcomas  general  cancer forms changes (mutations) happen dna cells  dna inside cell packaged large number individual genes  contains set instructions telling cell functions perform  well grow divide  mutations tell cells grow divide uncontrollably continue living normal cells die  happens  accumulating abnormal cells can form tumor  cells can break away spread (metastasize) parts body  risk factors factors can increase risk sarcoma include:  inherited syndromes  syndromes increase risk cancer can passed parents children  examples syndromes increase risk sarcoma include familial retinoblastoma neurofibromatosis type 1  radiation therapy cancer  radiation treatment cancer increases risk developing sarcoma later  chronic swelling (lymphedema)  lymphedema swelling caused backup lymph fluid occurs lymphatic system blocked damaged  increases risk type sarcoma called angiosarcoma  exposure chemicals  chemicals  industrial chemicals herbicides  can increase risk sarcoma affects liver  exposure viruses  virus called human herpesvirus 8 can increase risk type sarcoma called kaposi's sarcoma people weakened immune systems                    mayo clinic staff mayo clinic staff  sarcoma care mayo clinic 
sarcoma