Osteosarcoma is the most common form of bone cancer. It is believed to originate from primitive mesenchymal cells but also may arise from pluripotential mesenchymal cells. Osteosarcoma is a deadly cancer and is commonly fatal when it metastasizes to the lungs. It usually forms as a single lesion on children's long bones, especially the distal femur, proximal humerus and proximal tibia. The following steps will show how to diagnose an osteosarcoma.
Expect patients to have symptoms for weeks or months before seeking treatment. Osteosarcomas most commonly cause pain, especially with activity. A history of swelling, depending the size and location, also may exist.
Conduct a physical examination. Patients with osteosarcoma may have a palpable mass that may be warm and tender. The involvement of a joint will decrease its range of motion.
View the suspected lesion with radiographs. No single feature will confirm the diagnosis of an osteosarcoma because 45 percent of cases are osteoblastic and 30 percent of cases are osteolytic. The periosteum may be elevated and appear as the Codman triangle and the tumor usually extends through the bone in a sunburst appearance.
Perform a Craig needle or incisional biopsy. This is usually performed by an orthopedic surgeon who must communicate with the pathologist about the amount of tissue required.
Examine the histology of the tissue sample. The presence of osteoid is characteristic of osteosarcoma. Stromal cells may have irregular nuclei and be spindle-shaped.