title: Cystic pancreatic neuroendocrine tumors: the value of cytology in preoperative diagnosis.
abstract: BACKGROUND
  Cystic pancreatic neuroendocrine tumors (cPanNETs) account for 13% to 17% of PanNETs. Although the value of endoscopic ultrasound (EUS) imaging and cyst fluid analysis (CFA) in their preoperative diagnosis has been well described, limited information is available about the diagnostic role of cytology samples obtained from fine-needle aspiration (FNA).
  
  
  METHODS
  Cytopathology records between 1992 and 2013 were searched for all reports of cysts interpreted as PanNET. Patient demographics, clinical and radiologic information, CFA, histopathology, and cytopathology findings were recorded. Performance characteristics of cytology and EUS for the accurate diagnosis of cPanNET were calculated.
  
  
  RESULTS
  In total, 35 FNAs from 33 patients with cPanNETs were identified, and 34 EUS were performed. Cytology made a specific diagnosis of a cPanNET in 71% of the biopsies compared with a specific diagnosis by EUS in 38% of cases. An interpretation of suspicious for cPanNET was given in 77% of cases by cytology and in 47% by EUS. Cytology identified 86% of the lesions as high-risk pancreatic cysts compared with 56% by EUS. Diagnostic morphology was present on both cytology and cell block preparations in 60% of aspirates, on cytology only in 20%, and on cell block only in 20%. CFA was performed on 51% cyst fluids. All cysts but 1 revealed low carcinoembryonic antigen levels (range, 0.2 to >500 ng/mL; mean, 29.5 ng/mL), and amylase levels were <500 U/L in all but 2 cases (range, 16-1493 U/L; mean, 205 U/L).
  
  
  CONCLUSIONS
  Cytology is the most accurate test for preoperative diagnosis of cPanNETs. EUS is insufficiently accurate for independent diagnosis, and carcinoembryonic antigen and amylase analyses are noncontributory.
authors.affiliation: Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Vicente
authors.initials: V
authors.lastname: Morales-Oyarvide
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Yoon
authors.forename: Thun
authors.initials: T
authors.lastname: Ingkakul
authors.forename: David G
authors.initials: DG
authors.lastname: Forcione
authors.forename: Brenna W
authors.initials: BW
authors.lastname: Casey
authors.forename: William R
authors.initials: WR
authors.lastname: Brugge
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernández-del Castillo
authors.forename: Martha B
authors.initials: MB
authors.lastname: Pitman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000681:Amylases / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D002272:Carcinoembryonic Antigen / Q000032:analysis; D020420:Cyst Fluid; D003581:Cytodiagnosis; D019160:Endosonography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000601:surgery; D010181:Pancreatic Cyst / Q000175:diagnosis* / Q000601:surgery; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D011300:Preoperative Care; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D002272:Carcinoembryonic Antigen; D000681:Amylases
keywords: cytology; endoscopic ultrasound-guided fine-needle aspiration; pancreatic cyst; pancreatic endocrine tumor