Epithelial hyperplasia of the gallbladder in children with anomalous pancreaticobiliary ductal union

BACKGROUND/AIMS: Few data are available on the fate and incidence of epithe lial hyperplasia throughout the life of anomalous pancreaticobiliary ductal union (APBD) patients. The pathological study in pediatric APBD patients i s less recognized. METHODOLOGY: Ten resected gallbladders obtained from children with APBD and control patients without APBD were examined histologically, and immunohist ochemically for the detection of Ki-67 las a proliferative marker) and p53. K-ras mutations in codon 12 were also examined. Epithelial hyperplasia was classified into high-grade and low-grade hyperplasia. RESULTS: Six (60%) of 10 patients with APBD had epithelial hyperplasia of t he gallbladder, whereas no patients without APBD exhibited this lesion. Dif fuse epithelial hyperplasia was observed in 1 (50%) of 2 undilated-type APB D and 5 (63%) of 8 dilated-type. Two (33%) of 6 patients with epithelial hy perplasia exhibited high-grade hyperplasia. Ki-67 labeling index (LI) was s ignificantly higher in hyperplastic mucosa than in control gallbladder muco sa. K-ras mutations and p53 overexpression were not detected in hyperplasti c and normal mucosa. CONCLUSIONS: Epithelial hyperplasia of the gallbladder accompanied by incre ased proliferative activity exists at birth or is acquired in childhood wit h APBD patients and may be an important factor predisposing to the developm ent of gallbladder carcinoma.