title: Endoscopic ultrasound-guided fine needle aspiration cytology of pancreatic neuroendocrine tumours: cytomorphological and immunocytochemical evaluation.
abstract: OBJECTIVE
  Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) is increasingly used in preoperative localization and diagnosis of pancreatic neoplasms including neuroendocrine tumours (NETs). The objective of the present study was to identify the cytological features of pancreatic NETs obtained by EUS-FNA.
  
  
  METHODS
  The study group consisted of nine cases of pancreatic tumours correctly diagnosed or strongly suggestive of NETs based on EUS-FNA. Cytological smears were retrospectively reviewed. The clinical data and immunocytochemical stains applied to the cell block preparations were also reviewed and examined.
  
  
  RESULTS
  All cases except one showed characteristic cytomorphological features sufficient for their recognition and separation from pancreatic adenocarcinoma and other lesions. The most helpful cytological features that facilitated the cytological diagnosis of NET were a richly cellular aspirate with a monotonous, poorly cohesive population of small cells with a speckled or dusty chromatin pattern and plasmacytoid morphology. The neuroendocrine differentiation of these tumours was further confirmed by immunocytochemistry.
  
  
  CONCLUSIONS
  EUS-FNA is a valuable method in the recognition of pancreatic NETs. By adherence to the characteristic cytomorphological criteria of pancreatic NET together with collection of suitable material for ancillary immunocytochemical stains, cytopathologists could reach a correct diagnosis in most instances.
authors.affiliation: Department of Histopathology, St Thomas' Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK. fuju.chang@gstt.nhs.uk
authors.forename: F
authors.initials: F
authors.lastname: Chang
authors.forename: C
authors.initials: C
authors.lastname: Vu
authors.forename: A
authors.initials: A
authors.lastname: Chandra
authors.forename: J
authors.initials: J
authors.lastname: Meenan
authors.forename: A
authors.initials: A
authors.lastname: Herbert
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D003937:Diagnosis, Differential; D019160:Endosonography / Q000379:methods*; D004847:Epithelial Cells; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000473:pathology; D010179:Pancreas / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D011446:Prospective Studies; D016896:Treatment Outcome