title: False-positive finding of retropharyngeal lymph node recurrence in both fluorine (18)FDG PET and MRI in a patient with nasopharyngeal carcinoma.
abstract: BACKGROUND
  Biopsy of the retropharyngeal node is not routinely accessible. The diagnosis of retropharyngeal lymph node recurrence in patients with nasopharyngeal carcinoma (NPC) is often based on an imaging study.
  
  
  METHODS
  We reported a patient with NPC who was incorrectly diagnosed with left retropharyngeal lymph node recurrence by both MRI and positron emission tomography (PET)/CT.
  
  
  RESULTS
  A woman who was treated for stage IVA NPC 2 years previously was found to have a nodal lesion in the left retropharyngeal space on MRI together with focal fluorodeoxyglucose (FDG) uptake on PET/CT. Locoregional recurrence was suspected, and surgery was performed. Subsequent pathology results showed reactive lymphoid hyperplasia.
  
  
  CONCLUSIONS
  Although tissue biopsy for the retropharyngeal node is technically difficult, this case demonstrates that tumor recurrence cannot be diagnosed even based on both positive findings on MRI and PET/CT in patients with NPC.
authors: Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors: Ming-Chen
authors: MC
authors: Tsai
authors: Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors: Yu-Chi
authors: YC
authors: Shu
authors: Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors: Chia-Chen
authors: CC
authors: Hsu
authors: Department of Pathology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan.|Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors: Chih-Kung
authors: CK
authors: Lin
authors: Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors: Jih-Chin
authors: JC
authors: Lee
authors: Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors: Yueng-Hsiang
authors: YH
authors: Chu
authors: Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.|Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
authors: Wen-Yen
authors: WY
authors: Huang
mesh_terms: D000328:Adult; D001706:Biopsy; D003951:Diagnostic Errors; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging*; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: MRI; locoregional recurrence; nasopharyngeal carcinoma; positron emission tomography; retropharyngeal lymph node