Pancreaticobiliary maljunction without biliary dilatation in pediatric patients.

PURPOSE: Pancreaticobiliary maljunction (PBM) without biliary dilatation is a condition in which dilatation of the bile duct is not seen in patients with PBM. Recently, the Japanese Study Group on Pancreaticobiliary Maljunction (JSGPM) published new diagnostic criteria for PBM. In these criteria, biliary dilatation is defined according to the standard diameter at each age. We reviewed cases of pediatric patients with PBM without biliary dilatation. METHODS: From 1992 to 2019, 134 patients with PBM were treated in our institution. Among these, 7 patients were retrospectively diagnosed with PBM without biliary dilatation. The clinical information was retrospectively assessed in these patients. RESULTS: Of the seven patients, six were female. All patients had symptoms similar to those of patients with congenital biliary dilatation. In all seven patients, the diagnosis of PBM was made before definitive surgery. Six patients had type B PBM, and one had type D PBM. All patients underwent extrahepatic bile duct resection and hepaticojejunostomy, and their symptoms resolved. One patient experienced postoperative complications of anastomotic leakage followed by anastomotic stricture. CONCLUSION: The present report revealed important clinical features of this entity. However, there are still some issues that need to be discussed, and further research is needed.

Impact of DNA double-strand breaks on pancreaticobiliary maljunction carcinogenesis.

BACKGROUND: Pancreaticobiliary maljunction (PBM) is a condition characterized by chronic inflammation due to refluxed pancreatic juice into the biliary tract that is associated with an elevated risk of biliary tract cancer. DNA double-strand breaks (DSBs) are considered the most serious form of DNA damage. DSBs are provoked by inflammatory cell damage and are recognized as an important oncogenic event in several cancers. This study used γ-H2AX, an established marker of DSB formation, to evaluate the impact of DNA damage on carcinogenesis in PBM. METHODS: We investigated γ-H2AX expression immunohistochemically in gallbladder epithelium samples obtained from 71 PBM cases and 19 control cases. RESULTS: Fourteen PBM cases with gallbladder adenocarcinoma were evaluated at non-neoplastic regions. A wide range of nuclear γ-H2AX staining was detected in all PBM and control specimens. γ-H2AX expression was significantly higher in PBM cases versus controls (median γ-H2AX-positive proportion: 14.4 % vs. 4.4 %, p = 0.001). Among the PBM cases, γ-H2AX expression was significantly higher in patients with carcinoma than in those without (median γ-H2AX-positive proportion: 21.4 % vs. 11.0 %, p = 0.031). CONCLUSIONS: DSBs occurred significantly more abundantly in the PBM gallbladder mucosa, especially in the context of cancer, indicating an involvement in PBM-related carcinogenesis.