Osteosarcoma with Pathological Fracture: A Rare Case Report

Introduction: Osteosarcoma is a primary malignant bone tumor originating from stem cells and is characterized by the proliferation of tumor cells that directly form immature bone or bone-like tissue. Osteosarcoma represents only 3% to 5% of all spinal malignancies. The aim of study is to discuss the importance of diagnostic investigation for a relatively rare case of spinal osteosarcoma. Case presentation: A 49 years old female came to the Emergency Unit, with a chief complaint of bilateral weakness of lower extremities for 1 year and worsening in 2 weeks. Upon examination, the initial diagnosis was mistaken for a spinal canal stenosis because metastatic bone disease from previous history of malignant melanoma. Subsequently, a decompression with stabilization fusion and biopsy is performed. Primary osteosarcoma was confirmed from histopathology results. Further chemotherapy is planned referring to confirmed primary osteosarcoma on histopathology. Discussion: Spinal osteosarcoma is very rare. Osteosarcoma occurs most frequently in the appendicular skeleton, especially the distal femur and proximal tibial metaphysis, which account for 90% of all cases. Primary osteosarcomas of the vertebral column are uncommon and occur dominantly in the vertebral body. Biopsy remains the gold standard of care for diagnosis. Conclusion: The performance of MRI and pathologic evaluation with immunohistochemistry is particularly important for the differential diagnosis of soft tissue tumors. Histopathologic analysis also plays an important role in differentiating from metastatic bone disease. An aggressive treatment plan and long-term follow-up are mandatory in managing this case. Keywords: osteosarcoma, spinal osteosarcoma, spinal canal stenosis, malignancy, pathological fracture, rare case.