A tumor is an abnormal tissue mass that forms when the cells in our body start dividing uncontrollably or do not die when they are supposed to. Musculoskeletal tumors are tumors that develop in muscles, bones and nerves. They can be classified as benign or malignant, and primary or secondary in nature. A benign tumour is a non-cancerous growth that does not intrude nearby tissues or spread to other parts of the body. A malignant tumor is cancerous destroying nearby tissues and can spread to other parts of the body. Primary malignant musculoskeletal tumors originate in muscle or bone whereas secondary tumors have spread from elsewhere in the body to the muscles or bones.