title: Cytological analysis of small branch-duct intraductal papillary mucinous neoplasms provides a more accurate risk assessment of malignancy than symptoms.
abstract: OBJECTIVE
  The Sendai guidelines for management of patients with clinically suspected intraductal papillary mucinous neoplasms (IPMN) recommend resection of cysts > 30 mm, a dilated main pancreatic duct (MPD) > 6 mm, a mural nodule (MN), symptoms or positive cytology. Although sensitive, asymptomatic cysts, nonspecific symptoms, and a high threshold for positive cytology limit the specificity of the guidelines. We have assessed the value of cytology relative to symptom for predicting malignancy in IPMNs without high-risk imaging features.
  
  
  METHODS
  We retrospectively reviewed the clinical, radiological, and cytological data of 31 small branch-duct IPMNs without a MN. The cytological presence of high-grade atypical epithelial cells (HGA) was considered true positive, with a corresponding histology of high-grade dysplasia or invasive carcinoma. The performance of cytology versus symptoms was evaluated by calculating the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy.
  
  
  RESULTS
  The sensitivity (0.80), specificity (0.85), and accuracy (0.84) of HGA were higher than the corresponding performance characteristics of symptoms (0.60, 0.45, and 0.48, respectively). The NPV of no HGA on cytology was > 95%.
  
  
  CONCLUSIONS
  Cytology is a better predictor of malignancy than symptoms, for the conservative management of small branch-duct IPMNs. Cytology contributes to a highly accurate triple negative test for malignancy in small IPMN: No dilated MPD, MN or HGA.
authors.affiliation: Department of Pathology, Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
authors.forename: Jill
authors.initials: J
authors.lastname: Ono
authors.forename: Kurt A
authors.initials: KA
authors.lastname: Yaeger
authors.forename: Muriel
authors.initials: M
authors.lastname: Genevay
authors.forename: Mari
authors.initials: M
authors.lastname: Mino-Kenudson
authors.forename: William R
authors.initials: WR
authors.lastname: Brugge
authors.forename: Martha B
authors.initials: MB
authors.lastname: Pitman