Biliary Intraepithelial Neoplasia (BilIN) in Primary Sclerosing Cholangitis: The First Report from Iran

BACKGROUND Primary sclerosing cholangitis (PSC) as one of the most common chronic cholestatic liver diseases is a main predisposing factor for the development of cholangiocarcinoma (CCA). Biliary intraepithelial neoplasia (BilIN) is defined as precancerous bile duct epithelial changes, which can be eventually led to cholangiocarcinoma. There are very few studies about the frequency of BilIN in the patients with PSC and its correlation with paraclinical findings. OBJECTIVES In this study, we tried to find the frequency of BilIN in the patients with PSC and correlate its presence with clinicopathologic factors. METHODS During two years (2014 - 15) of investigation, 80 explanted livers with the confirmed diagnosis of PSC were studied through precise inspection and thorough sectioning of the explanted livers. These findings were correlated with paraclinical findings to identify any predictor of these neoplastic epithelial changes. RESULTS During the study period of 2 years, among 80 livers with confirmed diagnosis of PSC, there were 43 cases with different types of metaplasia. The frequency of epithelial changes was as below: 29 (35%) for pyloric metaplasia, 9 (10.8%) for mucinous metaplasia, 3 (3.6%) for intestinal metaplasia, 1 (1.2%) for osteoid metaplasia, and 1 (1.2%) for squamous metaplasia. There was no epithelial dysplasia in the study sample; however, according to the most recent reports, mucinous metaplasia is considered as BilIN 1; therefore, there would be 9 cases of BilIN I. There has been no statistically significant difference between PSC cases and those with BilIN in demographic variables, except for bilirubin and CA19-9 which were higher in the PSC cases with BilIN. CONCLUSIONS This study showed that the frequency of BilIN was low among Iranian patients with PSC. High bilirubin and CA19-9 can be predictors of the development of bile duct epithelial changes in patients with PSC.