MORPHOLOGICAL FEATURES OF BILE DUCTS AND THEIR LYMPHOID STRUCTURES IN NORMAL CONDITIONS AND IN CONGENITAL BILIARY ATRESIA

Abstract

The article presents the results of a research study aimed at identifying the morphological and morphometric characteristics of the liver, intrahepatic and extrahepatic bile ducts and their lymphoid structures in normal conditions and congenital biliary atresia. The study was conducted on 140 cadavers of both sexes at different ages of human ectopic development. The liver, intrahepatic, and extrahepatic bile ducts were examined under a light-optical microscope after being stained with hematoxylin-eosin, methylene blue and Van Gison's method and then studied under a "Topica TP1002DS" (Germany) light-optical microscope, and their semi-thin (0.5-1.0 μm) and ultrathin (70-100 nm) sections were examined in a JEM1400 (Jeol, Japan) transmission electron microscope. Furthermore, pathological-anatomical examinations of cadavers from newborns with congenital biliary atresia were also conducted using the same methods. The study showed that the bile ducts, lymphoid nodules, diffuse lymphoid tissue, and intraepithelial lymphocytes are found in the extrahepatic bile ducts, while lymphoid nodules are not found in the intrahepatic bile ducts. Morphometric indicators of the lymphoid structures of both the extrahepatic and intrahepatic bile ducts reached their maximum value in early childhood, and their value decreased in later age periods. Lymphoid structures of these bile ducts contain lymphocytes of various sizes, macrophages, plasma cells, eosinophils, mitotic and degenerative cells, and small lymphocytes predominate in the composition of lymphoid formations. In congenital biliary atresia, intraepithelial lymphocytes were not detected. The size and number of lymphoid structures decreased, while the number of degenerative cells increased.