2.1　Introduction

Fig.5.2　Pancreatic stones in human surgical specimens.Reprint with permission from shanghai science&technology press

Pancreatic stone is one of the features of chronic pancreatitis（CP）（Figs.5.2 and 5.3），and almost 90%patients had pancreatic stones in the course of CP（Mariani et al.1991）.Researches on the composition and formation of pancreatic stones will help to understand the pathophysiological process of CP.

The composition of pancreatic stone is almost clear.Outer region of pancreatic stones consists of calcium carbonate as a major component，while the inner part（nidus）is comprised of a very fine network of fibers which are composed of proteins and glycosaminoglycans.The possible related mechanisms included the decreasing secretion of pancreatic stone protein，much greater concentration of lactoferrin in pancreatic juice，precipitating of trypsin in early stage，overexpressing of osteopontin and GP-2 in human pancreatic juice.(https://www.daowen.com)

Fig.53.Pancreatic stones in human fecal.Reprint with permission from shanghai science&technology press