Seigo Yada

Histochemical and immunohistochemical studies on development of biliary carcinoma in forty-seven patients with choledochal cyst—Special reference to intestinal metaplasia in the biliary duct—

Histochemical and immunohistochemical studies on 47 consecutive specimens excised for choledochal cyst were performed to clarify possible metaplastic changes of the biliary duct in relation to carcinogenesis. An anomalous arrangement of the pancreaticobiliary ductal system was observed in all 39 cases examined. Among the 47 patients, 5 (10.6 per cent) had biliary carcinoma. 27.3 per cent mucous gland, 13.0 per cent goblet cell and 9.5 per cent argyrophil cell in 23 children. On the other hand, 81.8 per cent exhibited mucous gland, 41.7 per cent goblet cell and 27.3 per cent argyrophil cell in 24 adults. These metaplastic changes seemed to be an intestinal metaplasia and increased with age. Immunoreactive-gastrin or-somatostatin were evident immunohistochemically in 4 adults. These findings confirmed that intesinal metaplasia may develop in the biliary duct in cases of choledochal cyst. Although direct evidence between intestinal metaplasia and the development of biliary carcinoma was not found, reflux and stasis of pancreatic enzymes in the biliary duct may relate to the development of intestinal metaplasia and be an important factor related to the carcinogenesis of choledochal cyst.

Case report of an anomalous arrangement of the pancreaticobiliary ducts and nuclear DNA ploidy analysis

Two cases with an anomalous arrangement of the pancreaticobiliary ducts (APBD) are reported in order to investigate the mechanism of carcinogenesis of the extrahepatic biliary tract from the aspect of DNA ploidy analysis. Highly elevated biliary enzymes were found in both cases. Although inflammatory changes without any metaplasia or neoplasia were observed histologically, a cytofluorometric nuclear DNA ploidy analysis showed an aneuploid low ploidy pattern in a histogram of the gall bladder, an aneuploid high ploidy pattern in a histogram of the common bile duct in one patient, and a diploidy pattern in the gall bladder, an aneuploid low pattern in the common bile duct in another case. These results may show that APBD may play a role in the development in DNA ploidy abnormality with refluxed pancreatic juice which may induce repeated irritation and inflammation. Radical surgery including a complete excision of the extrahepatic biliary tract followed by reconstruction may achieve better results with regard to undesirable consequences with an abnormal nuclear DNA ploidy pattern and decrease the likelihood of developing carcinoma.