title: Sinonasal oncocytic Schneiderian papilloma accompanied by intravascular lymphoma: A case report on FDG-PET/CT imaging.
abstract: BACKGROUND
  F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is useful for the staging and assessment of treatment response in patients with lymphoma. Occasionally, benign lesions demonstrate avid FDG uptake and result in false positive findings.
  
  
  METHODS
  We report the case of an 82-year-old man presenting with cutaneous lesions, which were histopathologically diagnosed as intravascular lymphoma. FDG-PET/CT for staging demonstrated an FDG-avid mass extending from the right maxillary sinus to the nasal cavity, moderate uptake in the adrenal glands, mild uptake in the knee and the foot, and faint uptake in the skin and subcutaneous tissue of the legs. He subsequently underwent biopsy of the paranasal mass, which was diagnosed as oncocytic Schneiderian papilloma without lymphoma invasion. Glucose transporter (GLUT) 1 staining was highly positive in the papilloma cells, resulting in high FDG avidity. After completion of chemotherapy, the abnormal FDG uptakes in the skin, soft tissue, and adrenal glands disappeared on PET/CT. However, avid FDG uptake persisted in the sinonasal Schneiderian papilloma for 15 months before regression.
  
  
  CONCLUSIONS
  Benign tumors with oncocytic components may show avid FDG uptake. Therefore, correct diagnosis of oncocytic Schneiderian papilloma on FDG images is difficult when other accompanying malignant tumors, especially lymphoma, are present. If post-therapeutic PET/CT images show a discordant lesion, oncocytic tumors, albeit uncommon, should be considered in the differential diagnoses.
authors: Department of Nuclear Medicine Diagnostic Imaging Division of Pathology, The Cancer Institute Hospital of JFCR, Tokyo, Japan.
authors: Masamichi
authors: M
authors: Koyama
authors: Takashi
authors: T
authors: Terauchi
authors: Mitsuru
authors: M
authors: Koizumi
authors: Hiroko
authors: H
authors: Tanaka
authors: Kengo
authors: K
authors: Takeuchi
mesh_terms: D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008297:Male; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis* / Q000000981:diagnostic imaging; D010212:Papilloma / Q000175:diagnosis* / Q000000981:diagnostic imaging; D010255:Paranasal Sinus Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D000072078:Positron Emission Tomography Computed Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18