Silver-binding nucleolar organizer regions in hepatolithiasis and bile duct cancer

Hepatolithiasis and bile duct cancer have usually been linked together especially in Asian countries. Epithelium cells of bile duct or ductal glands had proliferative changes in patients with hepatolithiasis usually. The numbers and shape of the nucleoli were studied with special staining of AgNOR (Nucleolar Organizer Regions) on bile ducts without calculi (n = 11), with calculi (n = 21), and hepatolithiasis with bile duct carcinoma (n = 14). The patterns of AgNOR were classified into a dotted type and a cluster type under light microscopic examination. AgNORs scores were found to be 2.7 +/- 1.2 (M +/- SD) and 3.6 +/- 1.2 for intramural glandular cells and extramural glandular cells in hepatolithiasis (p < 0.05). In the cases of bile duct carcinoma, the percentage of the cluster form of AgNOR was 28.1 +/- 4.4%, and the scores were 4.7 +/- 2.4 for bile duct cancer, which was significantly different from intramural glands, but not different from the extramural glands in hepatolithiasis. High scores of the dotted type and high percentage of cluster type have high potentiality of malignant changes. From this study, unknown substances for malignant transformation might be secreted from the inner epithelium and or intramural glandular epithelium both of which are usually in contact with the infected bile and have chronic irritation from the stones. Extramural glands of the bile duct had higher potential for proliferation or malignant transformation in our study. Hence, long-term follow-up study of those patients with hepatolithiasis should be done very carefully especially due to the possibility of a combination of neoplastic changes in hepatolithiasis.