Case Report 627 Vol. 18, No. 7, 2004 Annals of Nuclear Medicine Vol. 18, No. 7, 627–630, 2004 CASE REPORT Received March 17, 2004, revision accepted June 23, 2004. For reprint contact: Ersoy Kekilli, M.D., Department of Nuclear Medicine, Inonu University, Turgut Ozal Medical Center, Elazig Avenue, 7. km. Malatya, TURKEY. E-mail: ekekilli@inonu.edu.tr INTRODUCTION FIBROUS DYSPLASIA of bone is a congenital, sporadic, developmental condition. 1 The pathogenetic abnormality is an expanding fibrous lesion of bone-forming mesen- chyma. 2 Fibrous dysplasia occurs with somatic activating mutations of the gene encoding the G S α subunit of the G protein that couples hormone receptors to adenylate cy- clase. The disease affects either sex and is generally diagnosed in childhood or adolescence. The clinical pic- ture of fibrous dysplasia can be monostotic or polyostotic. Some patients have characteristic hyperpigmented skin macules called cafe-au lait spots and endocrine hyper- function (i.e., McCune-Albright Syndrome). The endo- crinopathy is usually manifested as pseudoprecocious puberty in girls and less commonly thyrotoxicosis, Cushing syndrome, acromegaly, hyperprolactinemia, or hyper- parathyroidism. 3 Although serum calcium and phosphate levels are normal, serum alkaline phosphatase activity can be increased. Monostotic disease is more common, but any bone can be affected. The femur, tibia, ribs, and facial bones are most frequently involved. Spontaneous im- provement does not occur. Skeletal lesions may progress, and new ones may appear, but in most patients mild disease stays quiescent. 4 No established medical treat- ment exists for the skeletal disease; however promising responses have been reported with intravenous admin- istration of pamidronate. 5 Increased uptake of radio- pharmaceuticals is usually observed on affected bones scintigraphically but hepatic uptake is an unexpected finding. Here we present a case of fibrous dysplasia with diffuse hepatic uptake detected on bone scan. CASE REPORT A twenty-five year old male patient presented with back and chest pain which had worsened over the preceding two years. His physical examination was normal. Chest X-ray and computerized tomography revealed multiple expansile destructive cystic lesions in the ribs and lytic lesions in the fourth, fifth and sixth thoracic vertebrae. A Tc-99m-MDP bone scan showed increased activity ac- cumulation on the left ribs from 1st to 11th; right 4th and 5th ribs, lumbar 3rd and 4th vertebrae and base of the Pathologic hepatic Tc-99m-MDP uptake in polyostotic fibrous dysplasia Ersoy KEKILLI,* Cengiz YAGMUR,* Akin KUZUCU,** Omer SOYSAL,** Ayse Sertkaya CIKIM**** and Kadir ERTEM*** Departments of *Nuclear Medicine, **Thoracic Surgery, ***Endocrinology and ****Orthopedic and Traumatology, Inonu University, Turgut Ozal Medical Center, Malatya, Turkey 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. Key words: fibrous dysplasia, hepatic, extra-osseous