title: Unexpected finding of elevated glucose uptake in fibrous dysplasia mimicking malignancy: contradicting metabolism and morphology in combined PET/CT.
abstract: Fibrous dysplasia is a common benign disorder of bone in which fibro-osseous tissue replaces bone spongiosa. Lesions have a typical appearance on computed tomography (CT) images and regularly show a markedly increased uptake in bone scintigraphy using (99m)Tc-labelled methylene diphosphonate ((99m)Tc-MDP) as radiotracer. The glucose avidity of these lesions depicted by positron emission tomography (PET) using the radiolabelled glucose derivative (18)F-fluoro-2-deoxy-glucose (FDG) is less well known since FDG-PET does not have a role in the assessment of this disease. However, single cases have been reported in which fibrous dysplasia was present in patients undergoing FDG-PET scanning for oncological reasons, and no significant FDG uptake was observed for lesions identified as fibrous dysplasia. We report on a 24-year-old man with known fibrous dysplasia who underwent combined FDG-PET/CT scanning because of suspected recurrence of testicular cancer. In contrast to prior reports, a markedly elevated uptake of FDG was seen in numerous locations that were identified as fibrous dysplasia by CT. Based on this result, we conclude that fibrous dysplasia may mimick malignancy in FDG-PET and that coregistered CT may help to resolve these equivocal findings.
authors.affiliation: Department of Nuclear Medicine, University Hospital of Münster, Germany. stegger@uni-muenster.de
authors.forename: Lars
authors.initials: L
authors.lastname: Stegger
authors.forename: Kai Uwe
authors.initials: KU
authors.lastname: Juergens
authors.forename: Sabine
authors.initials: S
authors.lastname: Kliesch
authors.forename: Dag
authors.initials: D
authors.lastname: Wormanns
authors.forename: Matthias
authors.initials: M
authors.lastname: Weckesser
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D018236:Carcinoma, Embryonal / Q000175:diagnosis / Q000188:drug therapy / Q000556:secondary / Q000601:surgery; D003131:Combined Modality Therapy; D003937:Diagnosis, Differential; D005266:Femoral Neoplasms / Q000175:diagnosis / Q000556:secondary; D005359:Fibrous Dysplasia, Polyostotic / Q000175:diagnosis*; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D049268:Positron-Emission Tomography; D011183:Postoperative Complications / Q000175:diagnosis; D012680:Sensitivity and Specificity; D013736:Testicular Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000601:surgery; D014057:Tomography, X-Ray Computed
chemical_list: D001786:Blood Glucose; D019788:Fluorodeoxyglucose F18