title: Multicentric Reticulohistiocytosis Mimicking Malignancy on 18F-FDG PET/CT.
abstract: We report the case of a 75-year-old woman who underwent F-FDG PET/CT to evaluate the recurrence of urothelial carcinoma. PET/CT showed F-FDG-avid muscles and lymph nodes, mimicking recurrence. However, F-FDG uptake was also seen in multiple joints and subcutaneous tissue, representing an uncommon finding for recurrence. Further history taking revealed she had been pathologically diagnosed with multicentric reticulohistiocytosis (MRH) from skin biopsy, and the F-FDG PET/CT findings were consistent with MRH, a rare systemic inflammatory granulomatous disease of unknown etiology. Knowledge of the characteristic F-FDG PET/CT features of MRH is important to differentiate MRH from malignancy.
authors.affiliation: From the Departments of *Nuclear Medicine, †Dermatology, and ‡Urology, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hotta
authors.forename: Ryogo
authors.initials: R
authors.lastname: Minamimoto
authors.forename: Daisuke
authors.initials: D
authors.lastname: Suzuki
authors.forename: Atsuko
authors.initials: A
authors.lastname: Takahashi
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D015614:Histiocytosis / Q000000981:diagnostic imaging*; D006801:Humans; D000072078:Positron Emission Tomography Computed Tomography; D012008:Recurrence; D014571:Urologic Neoplasms / Q000000981:diagnostic imaging*; D019459:Urothelium
chemical_list: D019788:Fluorodeoxyglucose F18