Background
Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. When first recognized, telangiectatic osteosarcoma was proposed to be a distinct clinical and pathologic entity.
On the basis of subsequent findings that provided a better understanding of the condition’s presentation and prognostic implications, telangiectatic osteosarcoma should be considered a variant of osteosarcoma.
It is an uncommon variant, accounting for 0.4-12% of all osteosarcomas.
Telangiectatic osteosarcoma appears as a painful, radiographically lytic mass lesion in the metaphyseal portion of the long bones. It is characterized by dilated, blood-filled vascular spaces lined by malignant osteoblasts. These osteoblasts are separated by fibrous septa, which contain the malignant cells, multinucleated giant cells, and tumor osteoid.