Tumors may be sclerotic (contained in a scleroticized rind), usually in combination with moth-eaten or
permeative bone destruction.
Furthermore, the relation cannot be located at that region on the
permeative model.
Osteosarcomas, as opposed to bone island, show aggressive growth, with cortical destruction, interrupted periosteal reaction, a soft tissue mass, and
permeative growth within the bone marrow.
(13) The tumour may involve both the extraconal and intraconal compartment, many cause
permeative bone destruction (50%).
When a mixed lytic and sclerotic, motheaten, or
permeative appearance is identified with cortical disruption and complex periosteal reaction in a young patient, diagnostic considerations may include osteosarcoma, Ewing's sarcoma, active osteomyelitis, and Langerhans cell histiocytosis.
(13) Cortical destruction is invariably present, with the pattern of bone destruction described as geographic, moth-eaten, and/or
permeative. A Codman triangle signifying periosteal new bone formation is a common occurrence.
Radiographic evaluation with plain films revealed a
permeative, moth-eaten lesion of the left proximal tibia.
Permeative bone destruction is another recognized pattern of osseous involvement which often has associated periosteal reaction and soft tissue disease.
The lesions may also appear as
permeative lesions with ill-defined borders and periosteal reaction.
(11) Important histologic features that distinguish it from osteoblastoma include presence of a compact solid proliferation of neoplastic cells in between the bony trabeculae (unlike the single row of osteoblasts seen in osteoblastoma),
permeative growth or infiltration beyond the confines of the tumor into adjacent bone or soft tissue, and high mitotic rate.
Classically, Ewing's is described as a diaphyseal-based,
permeative lesion with a wide ZOT and aggressive periostitis (Figure 13).