Preoperative Diagnosis of Intraductal Papillary Neoplasm of the Bile Duct Followed by Laparoscopic Hepatectomy: A Case Report

Introduction: Intraductal papillary neoplasm of the bile duct (IPNB) is associated with better prognosis than biliary cancer after curative surgery.Case report: We report a case of a 59-year-old woman who presented with an enlarging liver cyst with a mural nodule.Laboratory data indicated normal hepatobiliary function and tumor markers.Imaging revealed a lesion at liver segments 5 and 6, with dynamic computed tomography revealing slight enhancement of the nodule during the early phase, prolonged during the delayed phase.Results: Magnetic resonance cholangiopancreatography revealed that the tumor was connected to segment 5 of the bile duct.Endoscopic retrograde cholangiopancreatography confirmed dilation of the bilateral intrahepatic bile duct owing to mucin obstruction from the tumor.Biopsy results were negative for malignancy, leading to a diagnosis of IPNB.Consequently, laparoscopic posterior segmentectomy and segment 5 resection were performed (operative duration: 433 min; intraoperative blood loss: 25 mL).Postoperative recovery was uneventful, and pathological examination indicated intestinal-type glandular epithelium with no invasive characteristics.The pathological diagnosis was IPNB without an invasive pattern.The surgical margin was clear, and no recurrence was observed 1 year postoperatively.Conclusion: Although IPNB is rare and challenging to diagnose preoperatively, evaluation of horizontal tumor spread and laparoscopic hepatectomy are effective for noninvasive cases.