Figure 2: Choledochal cysts (a) ERCP showing the long common channel and dilatation of intra- and extrabiliary ducts. (b) Macroscopic view showing a huge head with abundant pancreatic tissue in the dorsoventral direction. (c) Immunohistochemical staining of pancreatic polypeptide (PP). Distinction between the ventral and dorsal pancreas was done based on immunohistochemistry for PP and the lobular structure. The ventral pancreas was divided into a PP-rich portion and a PP-poor portion immunohistochemically. RVP, right ventral pancreas; LVP, left ventral pancreas; DP, dorsal pancreas.