Implications of intestinal metaplasia of the gallbladder in children with pancreaticobiliary maljunction.

ABSTRACT

PURPOSE: Pancreaticobiliary maljunction (PBM) is associated with an increased frequency of gallbladder malignancy. Intestinal metaplasia is often observed in gallbladder disease and is a risk factor for gallbladder carcinoma in adults. The hyperplasia-dysplasia-carcinoma progression is one of the possible mechanisms involved in biliary carcinogenesis. In this study, we evaluate the gallbladders of children with PBM for intestinal metaplasia and other histological changes. METHODS: From January 1997 to July 2010, 45 children with PBM were treated at our institution. A total of 42 children were included in our analysis which included histology and medical record review. RESULTS: The median age was 2.9 years (range 1 month-16.5 years). The most common histological finding was villous-type mucosal hyperplasia, found in 24 patients (57.1%). Mucous gland metaplasia and goblet cell metaplasia were observed in 12 (28.6%) and 7 (16.7%) patients, respectively. There were no cases of malignancy. The intra-gallbladder amylase level in patients with mucosal hyperplasia was significantly elevated (81,373 ± 92,442 vs. 38,932 ± 61,466; p = 0.042). Patients with mucous gland metaplasia had significantly higher serum amylase levels (833 ± 1,214 vs. 343 ± 358; p = 0.024). CONCLUSION: The incidence of intestinal metaplasia is relatively high even in children with PBM. Such mucosal changes are related to cholangitis resulting from the regurgitation of pancreatic juice into the bile duct, which also causes hyperamylasemia via cholangio-venous reflux.