Biliopancreatic fistula caused by an intraductal papillary-mucinous tumor of the pancreas confirmed by biochemical analysis of mucin.

Intraductal papillary-mucinous tumor of the pancreas is occasionally accompanied by biliopancreatic fistula. However, it is difficult to show the inflow of mucin produced by the tumor into the common bile duct. To confirm the biliopancreatic fistula, the mucin-rich fraction was purified from the bile and stained with antimucin antibodies. Western blot analysis showed characteristic smear staining patterns for mucin molecules with three types of antimucin antibodies. Immunohistochemical analysis with the antibody showed significant signals of the cancer cells and the luminal content of the dilated pancreatic duct. These results showed that the bile contained an abundance of mucin, which was produced by the primary pancreatic tumor. In cases with intraductal papillary-mucinous tumor of the pancreas, biochemical analysis of mucin molecules in the bile can be of clinical use in consideration of pathological process of tumor progression.