Diagnosis

The variety and complexity of the pathogenic factors that underlie CP make its classification and diagnosis difficult.Over the past decades，no widely accepted classification system or established diagnostic criteria have emerged for CP.This is despite several meetings on the topic held in Marseilles（1963 and 1984），Cambridge（1984）and Rome（1985）which greatly improved our knowledge of the pathogenesis and diagnosis of CP（Buchler et al.2009）.The Marseilles symposium，organized by Henri Sarles，became a milestone of research into CP.In 1984，the Marseilles standard was revised，abandoning the concept of chronic recurrent pancreatitis，and constituting a relatively complete description of CP from the pathology，exocrine and endocrine function in spite of not being widely applicable in clinical practice.In 1988，the Marseille-Rome international conference classified CP into three types:chronic calcifying pancreatitis，chronic obstructive pancreatitis and chronic inflammatory pancreatitis，according to the specific pathological changes involved in CP.In 1998，the Zürich international classification system defined patient cohorts in patients undergoing surgery for CP（Ammann 1998）.

The clinical evaluation of CP depends mainly on computed tomography（CT），magnetic resonance imaging（MRI），endoscopic retrograde cholangiopancreatography（ERCP）and endoscopic ultrasonography（EUS）.With the development of X-ray investigation，McCune，Shorb and Moscovitz（1968）completed the first endoscopic cannulation of the ampulla of Vater in 1968，which made the diagnosis of CP much easier.In 1980，DiMagno and colleagues（DiMagno et al.1980）proposed the concept of ultrasonic endoscopy，for the first time combining an ultrasonic probe with gastroscopy.Thereafter，Vilmann and colleagues（1993）developed a new method of endoscopic ultrasound（EUS）-guided fine needle aspiration using an ultrasonic endoscope with a curved array transducer mounted in front of the optic lens.(https://www.daowen.com)

The early diagnosis of CP is still difficult today because of two problems：（1）the lack of a high sensitivity/specificity pancreatic exocrine function test，（2）the non-obviousness of the change in early chronic inflammation imaging.Recently，reports of EUS in the diagnosis of CP are increasing.EUS examination when the ultrasonic probe is close to the pancreas has the potential to obtain a clear image of the pancreas；tissue could be easily and safely obtained under EUS-guided biopsy.Therefore，the use of EUS for the early diagnosis of CP is quite promising.