Bone Cancer (Osteosarcoma) is the most common primary malignant bone tumour, excluding myeloma and lymphoma. There is a predilection for the metaphyseal region of tubular long bones. 50% of cases occur around the knee. Bone Cancer (osteogenic sarcoma) is a malignant connective (soft) tissue tumor whose neoplastic cells present osteoblastic differentiation and form tumoral bone.
In children, 5% of all cancers are seen as bone cancer. 75% of all cases occur in patients below the age of 20. Looking at the distribution of cases by age from here, a second peak in incidence occurs in the elderly, usually associated with an underlying bone pathology such as Paget's disease, medullary infarct, or prior irradiation.
In all cases, the tumor may be localized at the metaphyseal end of the long bones. Most often it affects the upper end of tibia or humerus, of lower end of femurus. The tumor is solid, hard, irregular ("fir-tree" aspect on X-ray examination) due to the tumor spicules of calcified bone radiating in right angles. Surrounding tissues are infiltrated. Microscopically: Tumor cells are very pleomorphic (anaplastic), some are giant, numerous atypical mitoses. These cells produce osteoid describing irregular trabeculae (amorphous, eosinophilic/pink) with or without central calcification (hematoxylinophilic/blue, granular) - tumor bone. Tumor cells are included in the osteoid matrix. Cartilage may be present. Presence of immature blood vessels (sarcomatous vessels lacking endothelial cells) favors the bloodstream metastasizing.
bone cancer symptoms
Symptoms of bone cancer will first appears as a lump in long bones. Muscles in the area will start to become weaker and may appear to "shorten" or feel tight. some individuals report the sensation upon palpation that the muscles themselves actually detach from the cancering area. Although more of a sign than a symptom, the affected bone portion is not as strong as normal bone matter.
Posted by Staff at June 15, 2005 7:13 AMblog comments powered by Disqus