Delayed Diagnosis of Osteosarcoma in an Adolescent: A Case Report

Background: Osteosarcoma is the most common primary malignant bone tumor in adolescents. Early recognition and intervention are essential to improving outcomes and preserving function. Misdiagnosis or delayed diagnosis is common in resource-limited settings due to nonspecific early symptoms and limited access to diagnostic tools. Case Presentation: A 16-year-old girl presented to an orthopedic clinic with a history of left shoulder pain and swelling following a fall. She was initially diagnosed with a closed proximal humeral fracture and managed conservatively. Further history revealed a prior, slowly progressive swelling and nocturnal pain for several months, managed empirically with antibiotics and analgesics at multiple primary care facilities. On examination, she was pale and had a firm, tender, warm swelling with prominent superficial veins. Radiographs revealed a destructive lesion with a sunburst periosteal reaction and a pathological fracture, consistent with osteosarcoma. Biopsy confirmed the diagnosis. The patient underwent limb disarticulation and was referred for chemotherapy. Conclusion: This case highlights the consequences of delayed diagnosis of bone tumors in low-resource settings. Persistent limb swelling and pain, especially in adolescents, should raise suspicion for malignancy. Early imaging and specialist referral are crucial for timely diagnosis and management.