Osteosarcoma is a malignant tumor that arises from multipotent mesenchymal cells with osteoblastic differentiation; these cells produce mineralized bone and/or osteoid [1–3]. Cartilage, cartilage matrix, and fibrous tissue may also be produced by the neoplastic cells [1]. Based on the predominant matrix observed on histology, tumors are subdivided into chondroblastic, fibroblastic, osteoblastic, and telangiectatic types [3]. Tumors can be further subdivided into low-, intermediate-, and high-grade types, with higher grades generally indicating greater risk of metastasis [3].