Emergency Surgery in High Volume Osteosarcoma of Left Proximal Humerus Due to Vascular Compromise: A Case Report

BACKGROUND Osteosarcoma is the most common type of malignant bone tumor arising from mesenchymal stem cell. When occurring on the proximal humerus, it is associated with poor outcomes; there are numerous neurovascular structures around proximal humerus. Unfortunately, the degree of vascular involvement in osteosarcoma is rarely evaluated and reported. Thus, we would like to highlight our case. CASE REPORT We reported a case of left proximal humerus osteosarcoma causing dead limb in a 14-year-old boy. The dead limb progressed in the span of 3 weeks. An emergency forequarter amputation (FQA) was conducted to prevent further complications such as septicemia and mortality. Two months after the surgery, the patient had improved quality of life. One year after, the patient had no local recurrence. However, there was a lung metastasis detected 9 months after the surgery. The patient died 13 months after the surgery. CONCLUSIONS Osteosarcoma of the proximal humerus can potentially compromise vascular structures. Early diagnosis and treatment are mandatory to prevent such complications.