Paget Disease of the Temporal Bone

Abstract

Paget disease of bone is a disorder of remodeling characterized by uncoupling of bone resorption and bone formation (1). It is thought to be caused by a slow virus infection. Paget disease can affect one or multiple bones in the systemic skeleton, including the temporal bone (1,2). Typically, there are three phases of activity in Paget disease affecting the systemic skeleton (1,2). The first or osteolytic phase demonstrates the prominent resorption of bone by numerous large osteoclasts. The second or mixed phase involves both osteoclastic and osteoblastic activities, creating a mosaic appearance typical of Paget disease. The third or osteoblastic phase is characterized by abundant osteoblastic activity and a prominent mosaic pattern. In the temporal bone, a fourth or remodeled phase, where areas of inactive osteoblastic pagetic bone are remodeled into healthier lamellar bone with distinct haversian canal systems, has been described (2).