Osteosarcoma

Osteosarcoma is a high-grade malignant tumour arising from osteoblast-precursor cells. Abnormal bone production and local invasion disrupt normal bone structure. The result is persistent deep pain, swelling, tenderness, stiffness, and reduced range of motion rather than a brief pain pattern that settles with rest. A weakened bone may fracture with little trauma. Sudden deformity, a new inability to bear weight, or a sharp increase in pain should therefore be treated as possible pathologic fracture until assessed. Do not massage the mass or force movement through the affected limb; support it in the prescribed position and obtain urgent clinical review. Pulmonary spread is a major staging concern. New cough, dyspnea, chest pain, or hemoptysis requires prompt assessment, but do not assume every respiratory symptom is metastasis: infection during chemotherapy is another time-sensitive possibility. Clinical trajectory check Link new findings to the underlying process and the compensatory response that is succeeding or failing. Reassess objective trends such as perfusion, oxygenation, mental status, pain pattern, labs, and response to time-limited interventions so the next action reflects improvement or deterioration rather than a memorized...