Table 2 Typical radiographic features of benign and malignant patellar tumors

Bone destruction

Geographic aspect

Permeative or moth-eaten aspect

Extent

Eccentric area or total patella

Eccentric area or total patella

Margins

Lobulated or sharp or rounded verge

Ill-defined verge

Cortex

Thinned or expanded or thinned and expanded change

Permeative or destroyed change

Periosteal shell

-

Rare

Sclerotic rim

Common

-

Periosteal reaction

-

Rare

Septation

Common

Common

Calcifications

Rare

-

Reactive bone

Rare

Rare

Pathologic fracture

Rare

Common

Invasion of surrounding tissue and joint involvement

Rare

Common