Oncological and Functional Outcomes after Hemicortical Resection and Biological Reconstruction Using Allograft for Parosteal Osteosarcoma of the Distal Femur

Figure 2

(a) Representative photomicrograph for histological evaluation with hematoxylin-eosin staining (original magnification: 200X): hypocellular tumor with spindle cells showing mild atypia arranged in fascicles in desmoplastic collagenous stroma. The histological results are compatible with parosteal osteosarcoma (PAOS). (b, c) Representative photomicrographs for immunohistochemical assessment displaying tumor cells positively immunostained for MDM-2 (original magnification: 400X) and CDK4 (original magnification: 400X), respectively, with nuclear location. (d) Representative photomicrograph of the slices for histological evaluation after tumor excision with hematoxylin-eosin staining (original magnification: 200X): parallel trabeculae of the well-formed woven bone with spindle neoplastic cells in collagenous stroma, while (e) the neoplastic population is characterized by mild cellularity and atypia (original magnification: 40X). (f) Representative photomicrograph for histological evaluation with hematoxylin-eosin staining showing clusters of moderate cellularity and moderate atypia in PAOS (original magnification: 40X).