periosteal osteosarcoma

Reconstruction

of bone defect with autograft fibula and retained part of tibia after marginal resection of periosteal osteosarcoma: a case report. The radiographs demonstrate thickened diaphyseal cortex and perpendicular periosteal reaction extending into the soft tissue in the anteromedial aspect of the tibia. a Anteroposterior view; b lateral view

wjso.biomedcentral.com • CC-by-4.0

Reconstruction

of bone defect with autograft fibula and retained part of tibia after marginal resection of periosteal osteosarcoma: a case report. Computed tomography reveals cortical thickening and extrinsic scalloping of the cortex without medullary involvement. a Axial image; b sagittal image

wjso.biomedcentral.com • CC-by-4.0

Lesions

involving the outer surface of the bone in children: a pictorial review. Periosteal osteosarcoma in the right proximal femur. Axial a and coronal b T2 images reveal high signal soft-tissue mass involving predominantly the vastus medialis and intermedius with cortical disruption and intraosseous extension at the anteromedial aspect of the right femur (arrow)

insightsimaging.springeropen.com • Open Access

Periosteal

osteosarcoma • Periosteal osteosarcoma - Ganzer Fall bei Radiopaedia

Thapa S, Periosteal osteosarcoma. Case study, Radiopaedia.org (Accessed on 04 Dec 2022) https://doi.org/10.53347/rID-40937 • CC by-nc-sa 3.0 (modified)

Radiopaedia • CC-by-nc-sa 3.0 • de

Periosteal osteosarcoma is a form of surface osteosarcoma.

Epidemiology

It is the second most common type of juxtacortical or surface osteosarcoma after parosteal osteosarcoma and accounts for 1.5% of all osteosarcoma cases. It affects a slightly older age group (10-20 years) cf. conventional osteosarcoma.

Pathology

Periosteal osteosarcoma arise from the inner germinative layer of periosteum. Cytologic grade of this tumor is higher than parosteal osteosarcoma and lower than conventional osteosarcomas, so it is considered as an intermediate grade osteosarcoma (grade 2). It predominantly contains chondroid matrix.

Location

lesions tend to be diaphyseal
femur and tibia most common, especially medial distal femur
arises from cortex, being attached to underlying cortex at origin; intramedullary extension is rare

Radiographic features

Typically seen as a broad-based surface soft-tissue mass causing extrinsic erosion of thickened underlying diaphyseal cortex and perpendicular periosteal reaction extending into the soft-tissue component:

predominantly chondroid matrix results in a lesion that is low in attenuation on CT images and hyperintense on T2 weighted MR images and tends to “wrap around” the circumference of the bone
a periosteal reaction common, as sunburst pattern (radiating from bone surface) or a Codman triangle

MRI

typically hypointense on both T1 and T2 sequences: may see bony spicules radiating from surface lesion (sunburst pattern)
it may appear hyperintense on T2 sequence which represents its chondroid matrix.
reactive marrow changes are commonly seen at MR imaging, but true marrow invasion is rare
it is difficult to differentiate periosteal osteosarcoma from the conventional high grade osteosarcoma at imaging, however conventional osteosarcomas involve entire circumference of cortex and show intramedullary extension.

Treatment and prognosis

A periosteal osteosarcoma is of intermediate grade with prognosis being better than conventional osteosarcoma, but not as good as parosteal osteosarcoma (which is usually low grade).