Other Rare Pseudotumoral Lesions

Abstract

Paget disease is a disorder in which progressive deformity of the skeleton is associated with thickening of the involved bone. It affects older persons with a male predominance. Patients present with pain and progressive deformity. Any portion of the skeleton may be involved, but the innominate bone is the common site, followed by the sacrum, lumbar, spine, skull, femur, and tibia. Radiologically, Paget disease has typical radiographic features, namely a sharply demarcated lucency associated with thickened cortex and medullary bone. Histologically, the bony trabeculae are thickened and irregular with multiple blue cement lines. Osteoblasts and osteoclasts are prominent, and the bone marrow is replaced with loose connective tissue. Calcitonin and bisphosphonates have shown promise in arresting the progress of the disease. Development into sarcoma can be expected in fewer than 1% of patients.