title: False-positive EUS-guided FNA cytology for solid pancreatic lesions.
abstract: BACKGROUND
  The currently accepted paradigm is that the false-positive (FP) rate for EUS-guided fine-needle aspiration (EUS-FNA) cytologic analysis of a pancreatic lesion is less than 1%.
  
  
  OBJECTIVE
  To assess the FP rate of EUS-FNA in patients who underwent surgical resection for presumed pancreatic cancer.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Tertiary-care referral center.
  
  
  METHODS
  This study involved 367 patients with solid pancreatic lesions in whom EUS-FNA cytology results were interpreted as positive or suspicious for malignancy, which resulted in subsequent surgical resection.
  
  
  METHODS
  Surgical resection.
  
  
  METHODS
  The FP diagnosis was defined as EUS-FNA cytology specimens being reported as "positive" or "suspicious for malignancy" but that were later proven to be benign on surgical pathology.
  
  
  RESULTS
  The FP rate for EUS-FNA was 4 of 367 (1.1%) when only "positive" cytology findings were interpreted as malignant and 14 of 367 (3.8%) when both suspicious and positive cytology findings were interpreted as malignant. Among the 4 cases falsely interpreted as positive, 1 was falsely diagnosed cytologically as a neuroendocrine tumor and 3 as adenocarcinomas. All FP specimens showed chronic pancreatitis on surgical pathology. The incidence of discordance between cytology and surgical pathology did not change over time (2000-2006: 8/188 [4.3%] vs 2007-2010: 6/179 [3.4%]; P = .79).
  
  
  CONCLUSIONS
  Retrospective study at a single center.
  
  
  CONCLUSIONS
  In a retrospective cohort trial, the FP rate for EUS-FNA of solid pancreatic lesions was 1.1%. Findings of the current study are in line with previous studies that have evaluated the FP cytology rates with EUS-FNA of solid lesions. FP cases transpired primarily as a result of cytologic misinterpretation in the setting of chronic pancreatitis.
authors: Division of Gastroenterology, Department of Internal Medicine, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania 19107, USA. ali.siddiqui@jefferson.edu
authors: Ali A
authors: AA
authors: Siddiqui
authors: Thomas E
authors: TE
authors: Kowalski
authors: Haroon
authors: H
authors: Shahid
authors: Sean
authors: S
authors: O'Donnell
authors: Joanna
authors: J
authors: Tolin
authors: David E
authors: DE
authors: Loren
authors: Anthony
authors: A
authors: Infantolino
authors: Shih-Kuang
authors: SK
authors: Hong
authors: Mohamad A
authors: MA
authors: Eloubeidi
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000473:pathology* / Q000601:surgery; D010179:Pancreas / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000601:surgery; D050500:Pancreatitis, Chronic / Q000473:pathology; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D018084:Ultrasonography, Interventional