Masses left behind by healed tissue after a fracture or by certain diseases such as bone tumors are called skeletal masses. The skeletal system, like other organs, can develop tumors from any tissue component or metastatic lesions from other organs. Tumors that invade the bone can occur in the bone cells, the hematopoietic component of the bone, the cartilage, and the fibrous or synovial component. Other tumors may arise from the muscles and nerves, blood vessels, and fatty tissue of the bone. Bone masses may not be felt at first, but may become swollen and painful when the mass is larger. Diagnosis of skeletal masses is based on: a. Symptoms and signs Pain in the affected area, localized lumps and swelling in the joints and limbs. The movement of the affected joints and limbs is restricted. Localized bones are usually found in flat bones, especially in the sternum, ribs, skull, clavicle, and mandible, etc. Localized bones are elevated, hard to touch or rubber-like soft and tough, with elasticity or sound when pressed, and localized pressure pain. The tumor tissue often infiltrates the nearby soft tissues, and bead-like changes in the sternum, ribs and jawbone joints can be seen in half of the patients. General radiography, angiography, lymphatic angiography and other examinations of the affected bones are performed. Pathological tissue biopsy 1.needle sampling examination, the success rate of which is 80-90%. 2.Excision of the affected part for sample examination. 3.Excision or scraping pathological examination: Histopathological examination is performed by the pathologist according to the pathological changes of the sectioned tissue for the final correct diagnosis.