Active Paget's disease of bone with normal biomarkers of bone metabolism: a case report and review of the literature.

Paget's disease of bone is a focal skeletal disorder characterized by the formation of structurally abnormal bone, skeletal deformities, and other complications leading to bone pain and significant disability. It can involve one or more areas in a single bone (monostotic) or multiple bones (polyostotic). Most of the time the disease is asymptomatic and the diagnosis is made incidentally by increased levels of bone metabolism markers, especially alkaline phosphatase and is confirmed by specific findings in radiographs and radionuclide bone scan. In this report, we describe the case of a 65-year-old female with clinical and radiological findings of active Paget's disease of bone, but with absence of abnormal biochemical markers. The patient was given a dose of 5 mg zoledronic acid intravenously with significant clinical improvement within the next 6 months. The present case not only shows that Paget's disease of bone can occur in the setting of normal markers of bone metabolism but also that, in such cases, the response to treatment can be monitored by improvement in the clinical picture or by correct evaluation of the imaging findings.