Correct!
3. Aggressive periosteal reaction
Lytic lesions typically appear as abnormally lucent bone, sometimes manifesting as a “punched out” appearance in the bones, focal osteolysis, or cortical destruction. Callus formation appears as smooth, well-formed periosteal reaction, this morphology commonly encountered with healed rib fractures. Smooth erosive change often appears as thinning of one margin of the osseous cortex and is commonly the result of a lesion adjacent to a bone slowly enlarging and exerting pressure on the affected bone. Osteoblastic lesions manifest as abnormally dense-appearing bones, or sclerotic, and may be encountered in isolation, as my occur with the commonly encountered enostosis, or “bone island,” as multifocal lesions in the context of metastatic disease, or in a number of metabolic bone conditions. See Figure 2.
Figure 2. Detail view of the frontal chest radiograph (Figure 1A) shows well-formed periosteal reaction (arrows) involving the left 10th-12th ribs.
Using the information above and presented in Figure 2, which of the following represents the least likely consideration for the patient’s imaging findings? (Click on the correct answer to be directed to the fifth of 11 pages)