Pathology of Paget ’ s disease of bone

Paget’s disease of bone is a common metabolic disorder, which is in most cases diagnosed on the basis of its radiographic findings. Its primary bone alterations and subsequent complications constitute a complex range of pathologic pictures, which may pose diagnostic difficulties upon histologic examination. This article illustrates the spectrum of pathologic features of Paget’s disease of bone and its complications, with emphasis on the differential diagnosis from a diagnostic standpoint. The areas in which the histopathologic diagnosis appears to be most relevant are the characterization of neoplasms that may arise in the course of the disease, and more importantly, their separation from benign pseudosarcomatous conditions.