title: Procedure-related, false-positive cytology results during EUS-guided FNA in patients with esophageal cancer.
abstract: BACKGROUND
  EUS is a standard staging procedure in esophageal cancer. For adequate staging, FNA of suspicious lymph nodes is recommended. Based on optimal staging, sophisticated treatment can be applied more properly. The working channel of the endoscope can potentially be contaminated by cancer cells derived from the luminal surface of esophageal cancer during EUS-guided FNA, which may result in false-positive cytology results of EUS-guided FNA of celiac lymph nodes.
  
  
  OBJECTIVE
  To determine whether passing an endoscope through intraluminal esophageal cancer can lead to contamination of the working channel with tumor cells.
  
  
  METHODS
  An ex vivo assessment of contamination of endoscope working channels.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  This study involved 13 patients with esophageal cancer.
  
  
  METHODS
  Working channels of endoscopes that had been used in patients with intraluminal esophageal cancer were studied immediately after EUS. A routine ex vivo FNA was performed through the endoscope on 8 patients. The same procedure was performed through the endoscope on 5 other patients after the working channel had been cleaned by extensive flushing.
  
  
  METHODS
  Semiquantitative scoring of cytology smears.
  
  
  RESULTS
  Six of 8 specimens contained carcinoma cells. No contamination by carcinoma cells or normal cells was observed when the working channel was flushed with tap water prior to the sham FNA procedure.
  
  
  CONCLUSIONS
  This was an ex vivo study of a limited group of patients.
  
  
  CONCLUSIONS
  The working channel of the endoscope can be contaminated during the EUS-guided FNA procedure. Cancer cell contamination can be avoided by flushing the endoscope.
authors.affiliation: Departments of Pathology, University Medical Center Groningen, 9700 RB Groningen, The Netherlands.
authors.forename: Bettien M
authors.initials: BM
authors.lastname: van Hemel
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Lamprou
authors.forename: Rinse
authors.initials: R
authors.lastname: Weersma
authors.forename: John T M
authors.initials: JT
authors.lastname: Plukker
authors.forename: Albert J H
authors.initials: AJ
authors.lastname: Suurmeijer
authors.forename: Hendrik M
authors.initials: HM
authors.lastname: van Dullemen
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology; D000368:Aged; D044963:Biopsy, Fine-Needle / Q000009:adverse effects* / Q000379:methods; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology; D019160:Endosonography / Q000009:adverse effects* / Q000295:instrumentation; D004866:Equipment Contamination; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D020701:Esophagoscopes / Q000009:adverse effects; D004945:Esophagoscopy / Q000009:adverse effects* / Q000379:methods; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D011379:Prognosis