title: Endoscopic ultrasound-guided needle-based confocal laser endomicroscopy in solid pancreatic masses.
abstract: OBJECTIVE
  The differential diagnosis of solid pancreatic masses by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is currently suboptimal in centers that are not equipped with rapid on-site evaluation. Needle-based confocal laser endomicroscopy (nCLE) enables real-time in vivo microscopic imaging during endoscopy. This study aimed to describe nCLE interpretation criteria for the characterization of pancreatic masses, with histopathological correlation, and to perform the first validation of these criteria.
  
  
  METHODS
  A total of 40 patients were evaluated by EUS-FNA combined with nCLE for the diagnosis of pancreatic masses. Final diagnosis was based on EUS-FNA histology and follow-up at 1 year. Five unblinded examiners defined nCLE criteria for adenocarcinoma, chronic pancreatitis, and neuroendocrine tumor (NET) using a set of video sequences from 14 patients with confirmed pathology (Step 1). These criteria were retrospectively validated by four independent, blinded examiners using sequences from 32 patients (Step 2).
  
  
  RESULTS
  nCLE criteria were described for adenocarcinoma (dark cell aggregates, irregular vessels with leakages of fluorescein), chronic pancreatitis (residual regular glandular pancreatic structures), and NET (black cell aggregates surrounded by vessels and fibrotic areas). These criteria correlated with the histological features of the corresponding lesions. In the validation review, a conclusive nCLE result was obtained in 75 % of cases (96 % correct). Statistical evaluation provided promising results, with high specificity, and negative and positive predictive values for all types of pancreatic masses.
  
  
  CONCLUSIONS
  Considering the low negative predictive value of EUS-FNA, nCLE could help to rule out malignancy after a previous inconclusive EUS-FNA. Larger studies are required to confirm these findings and to establish the role of nCLE in the diagnosis of pancreatic masses.
  
  
  BACKGROUND
  ClinicalTrials.gov (NCT01563133).
authors: Department of Hepatogastroenterology, Institut Paoli Calmettes, Marseille, France.
authors: Marc
authors: M
authors: Giovannini
authors: Department of Hepatogastroenterology, Institut Paoli Calmettes, Marseille, France.
authors: Fabrice
authors: F
authors: Caillol
authors: Department of Biopathology, Institut Paoli Calmettes, Marseille, France.
authors: Geneviève
authors: G
authors: Monges
authors: Department of Biopathology, Institut Paoli Calmettes, Marseille, France.
authors: Flora
authors: F
authors: Poizat
authors: Department of Biopathology, Centre Léon Bérard, Lyon, France.
authors: Anne-Isabelle
authors: AI
authors: Lemaistre
authors: Department of Gastroenterology, Ramsay Générale de Santé, Hôpital privé Jean Mermoz, Lyon, France.
authors: Bertrand
authors: B
authors: Pujol
authors: Medicosurgical Department of Hepatogastroenterology, Hôpital Saint-Philibert, Lomme-lès-Lille, France.
authors: Damien
authors: D
authors: Lucidarme
authors: Department of Gastroenterology, Clinique du Trocadéro, Paris, France.
authors: Laurent
authors: L
authors: Palazzo
authors: Department of Gastroenterology, Ramsay Générale de Santé, Hôpital privé Jean Mermoz, Lyon, France.
authors: Bertrand
authors: B
authors: Napoléon
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000379:methods*; D005260:Female; D005602:France; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000175:diagnosis / Q000473:pathology; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000473:pathology; D050500:Pancreatitis, Chronic / Q000175:diagnosis / Q000473:pathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013223:Statistics as Topic