Histopathological diagnosis of pancreatic intraepithelial neoplasia and intraductal papillary-mucinous neoplasms: interobserver agreement.
OBJECTIVE
The goal of this study was to evaluate the consistency of distinction between pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary-mucinous neoplasms (IPMN) and the hypothesis that guidelines for their distinction might be inadequate.


METHODS
A group of 93 pancreas specimens from surgical resections or autopsies that contained lesions consistent with histopathological diagnoses of PanIN-1A, PanIN-1B, PanIN-2, or IPMN (adenoma or borderline) was collected. The classification of these neoplasms by 6 pathologists, 2 from Europe, 2 from Japan, and 2 from the United States, was compared. The pathologists initially used guidelines current in their practice and then reviewed 47 of the 93 specimens a second time using new consensus definitions and guidelines for PanIN and IPMN that were developed in 2003.


RESULTS
The initial comparison showed frequent disagreement regarding both category and grade of the lesions. Agreement was greater for category than grade. In the second review, agreement among the 6 reviewers improved, remaining higher for category, although disagreements persisted for both category and grade.


CONCLUSIONS
We conclude that the new definitions of PanIN and IPMN improve the consistency in classifying these lesions, but additional work is needed to further improve the reproducibility of their classification.
Longnecker
Daniel S
DS
Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA. daniel.s.longnecker@dartmouth.edu
Adsay
N Volkan
NV
Fernandez-del Castillo
Carlos
C
Hruban
Ralph H
RH
Kasugai
Tsutomu
T
Klimstra
David S
DS
Klöppel
Günter
G
Lüttges
Jutta
J
Memoli
Vincent A
VA
Tosteson
Tor D
TD
Yanagisawa
Akio
A
Wilentz
Robb
R
Zamboni
Giuseppe
G
D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis / Q000473:pathology*; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis / Q000473:pathology*; D002291:Carcinoma, Papillary / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000473:pathology*