title: High FDG activity in focal fat necrosis: a pitfall in interpretation of posttreatment PET/CT in patients with non-Hodgkin lymphoma.
abstract: OBJECTIVE
  PET/CT has a major role in lymphoma imaging, but glycolytic activity in inflammatory processes can reduce specificity. In this study we evaluated restaging PET/CT findings in patients with non-Hodgkin lymphoma (NHL) and fat necrosis.
  
  
  METHODS
  We identified 16 patients from 8,819 restaging FDG PET/CT scans with suspicion of or biopsy-proven fat necrosis on PET/CT.
  
  
  RESULTS
  All patients had NHL and demonstrated focal FDG-avid nodular change on CT with density higher than that of fat but lower than that of soft tissue. Histological confirmation was obtained in eight patients, with high GLUT-1 staining between necrotic tissue and organizing fat necrosis evident. Uptake resolved in four patients, and surveillance was continuing in four without relapse.
  
  
  CONCLUSIONS
  Although rare, identification of fat necrosis in patients with a solitary FDG-avid nodule after therapy is important and may lead to the avoidance of unnecessary interventions or treatment. Specific features on CT aid identification, whilst follow-up imaging can be helpful as the metabolic abnormality regresses with time.
authors: Centre for Cancer Imaging, Peter MacCallum Cancer Centre, St Andrews Place, Melbourne, Australia 3002.
authors: Raghava
authors: R
authors: Kashyap
authors: Eddie
authors: E
authors: Lau
authors: Anupkumar
authors: A
authors: George
authors: John F
authors: JF
authors: Seymour
authors: Stephen
authors: S
authors: Lade
authors: Rodney J
authors: RJ
authors: Hicks
authors: Michael S
authors: MS
authors: Hofman
mesh_terms: D000328:Adult; D000368:Aged; D005189:False Positive Reactions; D005218:Fat Necrosis / Q000175:diagnosis*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
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