Gedik, Gonca KaraAta, OzlemKarabagli, PinarSari, Oktay2020-03-262020-03-2620141790-5427https://hdl.handle.net/20.500.12395/30744Brown tumor is one of the skeletal manifegtations of hyperparathyroidism. It is a benign but locally aggressive bone lesion and its differential diagnosis with giant cell containing skeletal tumors or metastases may be complicated. We present a male patient with chronic renal failure who was initially misdiagnosed as having a giant-cell rich neoplasm of bone in his right thumb. Diffusely increased fluorine-18 fluorodeoxyglucose (F-18-FDG) uptake in the axial and appendicular skeleton and multiple F-18-FDG avid lytic lesions suggesting multiple metastases were observed on the F-18-FDG positron emission tomography/computed tomography (PET/CT) scan. On the usual technetium-99m methylene diphosphonate (Tc-99m-MDP) bone scan we noticed diffusely increased uptake in the skeleton and two focuses with very much increased uptake, which suggested a metabolic bone disease rather than a multiple metastatic giant cell tumor or bone metastases. Additional investigation documentated increased levels of parathyroid hormone. Parathyroid hyperplasia was finally diagnosed with Tc-99m-methoxyisobutylisonitrile (MIBI) parathyroid scintigraphy. Fluorine-18-FDG avid lytic lesions were attributed to hyerparathyroidism associated brown tumors instead of multiple metastases. In conclusion, we present a patient with chronic renal insufficiency, who suffered from secondary and later from tertiary HPT with polyostotic brown tumors, which were best shown by the F-18-FDG PET/CT than by the Tc-99m-MDP or the Tc-99m-MIBI scans.eninfo:eu-repo/semantics/closedAccessGiant cells tumorBrown tumorHyperparathyroidismTertiary HPTPET/CT, Tc-99m-MDP and Tc-99m-MIBI scansArticle17321421725397627Q3WOS:000347437100013Q4