Pathologic hepatic Tc-99m-MDP uptake in polyostotic fibrous dysplasia.

Fibrous dysplasia of bone is a congenital, sporadic developmental disorder characterized by immature fibrous connective tissue and bone deformities. Hepatic Tc-99m-MDP uptake is a rare, serendipitous finding during bone scanning studies. The present patient was a 25-year-old male who had severe polyostotic fibrous dysplasia. On Tc-99m-MDP (methylene diphosphonate) bone scintigraphy, increased activity accumulations were seen on multiple ribs, vertebrae and base of the cranium. In addition, diffuse increased pathologic uptake of Tc-99m-MDP in the liver was shown. Intravenous pamidronate was administered monthly for two months. In the third week of the last administration Tc-99m-MDP bone scintigraphy was performed again, but despite sustained bone involvement, pathologic hepatic uptake was not seen on the scan. We thought that pathologic hepatic Tc-99m-MDP accumulation, may be related to the formation and aggregation of calcium oxalate and phosphate crystals which improved with pamidromat treatment.