EUS-based criteria for the diagnosis of chronic pancreatitis: the Rosemont classification.

Background: EUS is increasingly used in the diagnosis of chronic pancreatitis (CP). A number of publications in this field have used different EUS terminology, features, and criteria for CP, making it difficult to reproduce their findings and apply them in clinical practice. Moreover, traditional criteria such as the Cambridge classification for CP are arguably outdated and have lost their relevance.

Objective: Our purpose was to establish consensus-based criteria for EUS features of CP.

Design: Consensus study.

Main Outcome Measurements: Thirty-two internationally recognized endosonographers anonymously voted on terminology of EUS features, rank order, and category (major vs minor criteria). Consensus was defined as greater than two thirds agreement among participants.

Results: Major criteria for CP were (1) hyperechoic foci with shadowing and main pancreatic duct (PD) calculi and (2) lobularity with honeycombing. Minor criteria for CP were cysts, dilated ducts > or =3.5 mm, irregular PD contour, dilated side branches > or =1 mm, hyperechoic duct wall, strands, nonshadowing hyperechoic foci, and lobularity with noncontiguous lobules.

Limitation: Lack of broadly accepted reference standard.

Conclusion: In a complex disease such as CP that has no universally accepted reference standard, an EUS-based criterion for diagnosis can be determined by expert consensus opinion and the existing body of evidence. Here we present the new "Rosemont criteria" for the EUS diagnosis of CP.