Pamidronate treatment of bone fibrous dysplasia in nine children with McCune-Albright syndrome

McCune-Albright syndrome is a rare genetic disorder consisting of skin and bone dysplasia and peripheral endocrinopathies. Little data have been collected regarding bisphosphonate treatment of bone fibrous dysplasia in paediatric patients with this syndrome. The aim of our study was to investigate the therapeutic efficacy of pamidronate in these patients. Nine patients with moderate to severe forms of bone fibrous dysplasia were treated with pamidronate intravenously (0.5-1 mg/kg/daily for 2-3 d) at 0.5-1-y intervals. Patients were treated over a time period of 0.5-3.5 y. During treatment no spontaneous fracture occurred. Bone pain and gait abnormality due to pain disappeared after 2-3 therapeutic cycles. Cranial asymmetry and limb length discrepancy remained unchanged. Elevated serum alkaline phosphatase and urine hydroxyproline values were reduced by the treatment, demonstrating drug activity at the lesional level. The effectiveness of pamidronate was also seen at the non-lesional level through an increase in bone density. Radiographic and scintigraphic evidence of lesion healing was not attained. Pamidronate treatment can ameliorate the course of bone fibrous dysplasia in children and adolescents with McCune-Albright syndrome.