Fig. 1
From: The extremity localized classic osteosarcomas have better survival than the axial non-classics
a Representative hematoxylin-eosin staining of classic and non-classic high-grade osteosarcomas in this study. b Schematic figure showing the distribution of classic and non-classic high-grade osteosarcoma patients of this study. The three intersecting circles comprised age ≤ 40 years, extremity localized primary tumor, or free of metastasis at primary diagnosis, to illustrate the overlapping parts between the three elements of the definition of classic osteosarcoma