Endobronchial Metastasis From Osteosarcoma in an Adolescent: A Rare Case Report.

A 14-year-old female was diagnosed with osteosarcoma of the left proximal tibia and underwent neoadjuvant chemotherapy followed by wide local resection and limb-sparing surgery. Thirteen months after surgery, she developed coughing, wheezing, and shortness of breath. Chest CT revealed stenosis in the right main and middle bronchi with a soft-tissue density lesion. No suspicious metastatic lesions were observed around the airways, and the analysis of bronchoscopic biopsy specimens confirmed a rare endobronchial metastasis of osteosarcoma. Despite bronchoscopic intervention, the patient eventually died due to late detection and rapid tumor progression. These findings suggest that early bronchoscopic assessment of the airway mucosa is critical.