Expansile intramedullary lytic lesion involving the left humeral head with calcifications and narrow zone of transition.

Multiple cortical breach are noted.

Mild involvement of the scapula at the glenoid area is also noted.

There is no obvious soft tissue extension.

Impression: Chondrosarcoma

DDx: Osteosarcoma.

Why chondrossarcoma > osteossarcoma?

Radiograph of left humerus shows an large expansile, destructive lesion in the proximal humerus with marked overlying cortical destruction with extension of the lesion into the soft tissue. Codmans triangle also seen.

Telangiectatic osteosarcoma FINAL DIAGNOSIS

LEARNING POINTS: Telangiectatic osteosarcomas represent approximately 4% of all osteosarcomas and display distinctive pathologic features. The lesions are destructive and lytic, with large extraosseous masses incompletely surrounded by thin shells of bone. They grow rapidly and elicit relatively little bone reaction. Fluid-fluid levels may be demonstrated on CT or MRI.