title: Can EUS-guided FNA distinguish between gallbladder cancer and xanthogranulomatous cholecystitis?
abstract: BACKGROUND
  EUS-guided FNA (EUS-FNA) is a useful modality for sampling various targets, but its applicability to gallbladder (GB) mass lesions is limited.
  
  
  OBJECTIVE
  To determine the usefulness of EUS-FNA for diagnosing GB mass lesions.
  
  
  METHODS
  Single-center, retrospective, case-series study.
  
  
  METHODS
  Tertiary-care referral center.
  
  
  METHODS
  This study involved 15 consecutive patients who underwent EUS-FNA of GB mass lesions. We punctured GB masses in patients with suspected xanthogranulomatous cholecystitis to distinguish them from malignancy, and in patients with unresectable GB carcinoma for pathological confirmation. The final diagnosis was based on surgical histopathological results or follow-up outcome.
  
  
  METHODS
  EUS-FNA.
  
  
  METHODS
  Evaluation of EUS-FNA sampling adequacy rate and diagnostic yield.
  
  
  RESULTS
  Xanthogranulomatous cholecystitis was suspected in 6 of the 15 patients. EUS-FNA revealed foam cells (n = 3), inflammatory cells (n = 1, proven by cholecystectomy), and GB carcinoma (n = 1), and the amount of the aspirate was insufficient in one case (xanthogranulomatous cholecystitis was later proven by extended hepatectomy). The mean follow-up period of the patients with xanthogranulomatous cholecystitis was 1177 days. Adenocarcinoma was confirmed by EUS-FNA in 8 of the 9 patients with suspected unresectable GB carcinoma, and the FNA was inconclusive in one. All 10 patients with GB carcinoma underwent chemotherapy. The overall sampling adequacy was 86.6%. The accuracy of EUS-FNA for detecting malignancy and for the final diagnosis was 93.3% (95% CI, 62.4%-99.9%) and 80% (95% CI, 54%-93.7%), respectively.
  
  
  CONCLUSIONS
  A small patient cohort and a retrospective design with potential selection bias.
  
  
  CONCLUSIONS
  Malignant GB mass lesions can be safely and accurately differentiated by EUS-FNA. Thus, patients with xanthogranulomatous cholecystitis can avoid undue extensive surgery.
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, Chikusa-ku, Nagoya, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Hijioka
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Mekky
authors.forename: Vikram
authors.initials: V
authors.lastname: Bhatia
authors.forename: Akira
authors.initials: A
authors.lastname: Sawaki
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Mizuno
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hara
authors.forename: Waki
authors.initials: W
authors.lastname: Hosoda
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Kiichi
authors.initials: K
authors.lastname: Tamada
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Niwa
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamao
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D002764:Cholecystitis / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D019160:Endosonography; D005260:Female; D005704:Gallbladder / Q000000981:diagnostic imaging / Q000473:pathology; D005706:Gallbladder Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D006099:Granuloma / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D018084:Ultrasonography, Interventional; D014973:Xanthomatosis / Q000000981:diagnostic imaging / Q000473:pathology