Histological study of extrahepatic part of human biliary tree with emphasis on peribiliary glands

ABSTRACT

Extrahepatic part of human biliary tree was lined with simple tall columnar epithelium. Supranuclear cytoplasm of the cell was darkly stained. Histochemistry of the epithelium revealed that it was mucus secreting. Below the epithelium there was a thick compact layer of connective tissue. Outside the compact layer there was a loose layer of areolar tissue in which smooth muscle, blood vessels and nerves were found. Glandular acini were present within and outside the compact layer of intrapancreatic bile duct [IPBD] and common bile duct [CBD] whereas these were present only within the compact layer of bile duct of ampulla of Vater [BDAV]. Statistical significance of quantitative difference between glandular acini of BDAV with other regions revealed that the difference was significant [P < 0.01] with IPBD and non significant [P > 0.05] with CBD. Statistical significance of quantitative difference between glandular acini of IPBD with other regions revealed that the difference was significant [P < 0.01 and P < 0.05] with BDAV and CBD respectively. Statistical significance of quantitative difference between glandular acini of CBD with other regions also revealed that difference was significant [P<0.05] with IPBD whereas it was not significant with BDAV [P>0.05]. Intramural and extramural glandular acini were present in IPBD and CBD whereas BDAV contained only intramural glands. The difference between intramural and extramural glandular acini was statistically significant [P < 0.02] in IPBD. The difference between intramural and extramural glandular acini of CBD was also statistically highly significant [P<0.001]. Glandular acini as demonstrated by different stains were 100% mucous type in BDAV and IPBD whereas it was mixed type in CBD. The acini of CBD were serous, mucous and mixed type. The difference between serous and mucous, mucous and mixed glandular acini was statistically highly significant [P<0.001]. The difference between serous and mixed glandular acini was statistically not significant [P>0.05]. Ratio of serous, mucous and mixed glandular acini was 1221 respectively