title: Chemical-shift MRI of rebound thymic hyperplasia with unusual appearance and intense (18)F-FDG uptake in adulthood: report of two cases.
abstract: Rebound thymic hyperplasia (RTH) with increased (18)F-FGD uptake at positron emission tomography (PET) computed tomography (CT) is typical of pediatric patients after chemotherapy, although it may occasionally occur in adults. At CT, RTH usually appears as a diffusely enlarged thymus with areas of fatty attenuation. We report two cases of RTH in adults detected at follow-up: both showed unusual morphology on CT and were confirmed at PET-CT as areas of strongly increased radiopharmaceutical uptake, which suggested disease recurrence. Chemical-shift magnetic resonance imaging, however, demonstrated fat infiltration within the tissue. Such finding was consistent with the diagnosis of RTH and was paramount in preventing unnecessary invasive procedures or treatments.
authors.affiliation: Department of Radiology, San Luigi Gonzaga University Hospital, 10043 Orbassano (Torino), Italy. Electronic address: adriano.priola@inwind.it.
authors.forename: Adriano Massimiliano
authors.initials: AM
authors.lastname: Priola
authors.affiliation: Department of Radiology, San Luigi Gonzaga University Hospital, 10043 Orbassano (Torino), Italy.
authors.forename: Sandro Massimo
authors.initials: SM
authors.lastname: Priola
mesh_terms: D000328:Adult; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012008:Recurrence; D013950:Thymus Gland / Q000378:metabolism / Q000473:pathology; D013952:Thymus Hyperplasia / Q000175:diagnosis* / Q000378:metabolism*; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: (18)F-FDG PET-CT; Chemical-shift MRI; Computed tomography; Rebound thymic hyperplasia; Tumor