Imaging of periosteal osteosarcoma: radiologic-pathologic comparison

Area of Science:

• Orthopedic Oncology
• Radiology
• Pathology

Background:

• Periosteal osteosarcoma is a rare subtype of osteosarcoma.
• Accurate imaging diagnosis is crucial for appropriate management.

Purpose of the Study:

• To describe the characteristic imaging findings of periosteal osteosarcoma.
• To correlate imaging features with pathological findings.

Main Methods:

• Retrospective review of 40 pathologically confirmed periosteal osteosarcomas.
• Analysis of radiographs, CT, MR imaging, and bone scintigrams.
• Pathology reports were reviewed for histologic components and tumor grade.

Main Results:

• Most common locations: diaphysis of tibia (16) and femur (15).
• Imaging showed broad-based soft-tissue masses with cortical thickening, scalloping, and periosteal reaction.
• CT showed low attenuation and MR imaging showed high T2 signal intensity, reflecting chondroblastic components.
• Reactive marrow changes were common on MR imaging, but true invasion was rare.

Conclusions:

• Periosteal osteosarcoma presents as a surface mass with extrinsic cortical erosion and periosteal reaction.
• MR imaging can show reactive marrow changes, but true marrow invasion is infrequent.