We report a 52 years old male patient with Paget s disease involving the skull, whole spine and pelvis. Paget s disease is a localized disorder of bone remodeling. Increased osteoclasts and their activity initiate the process at affected skeletal sites, and the increase in bone resorption is followed by increased new bone formation, altering bone architecture. The signs and symptoms of Paget s disease are varied, depending on the location of the involved sites and the degree of increased bone turnover. Patients with polyostotic Paget s disease have increased urinary excretion of hydroxyproline and elevated serum alkaline phosphatase. In this case, initial serum alkaline phosphatase and osteocalcin had been increased but both of them were much decreased after 2 month-treatment with alendronate 40 mg per day. Urine N-terminal telopeptide of type I collagen was not elevated before treatment but has increased after treatment.
