Bone cancer is a sarcoma that starts in the bone. Bones are the support system of the body, together forming a skeleton which gives us shape and posture. There are several types of bone cancers, the most serious being primary bone cancers . Bone & Soft Tissue Cancer Here are the symptoms for bone cancer: Swelling or lump under the skin, most often in the arm or leg Pain, if the tumor is pressing on muscles or nerves Bloody or black stools Abdominal discomfort Numbness or weakness in arm or leg Bone fractures Symptoms For Soft Tissue Sarcoma: The location of the sarcoma makes a difference in the symptoms. For instance, if they start: · On the arms or legs, you may notice a lump that grows over a period of weeks to months. It may hurt, but it usually doesn’t. · In the retroperitoneum (the back wall inside the abdomen), they may cause problems ...