To investigate the diagnosis and treatments of intrahepatic intraductal papillary neoplasm of bile duct (IPNB) complicated with portal vein and biliary tract variations.

Clinical data of 1 patient with malignant transformation of intrahepatic IPNB complicated with portal vein and biliary tract variations admitted to Suzhou Hospital Affiliated to Nanjing Medical University in December 2020 were retrospectively analyzed. A 65-year-old female patient was admitted to hospital due to "recurrent upper abdominal discomfort for more than 4 years". No obvious positive sign was found in physical examination. No evident abnormality was found in routine blood test, liver function and tumor markers. Significant dilated bile duct in the left lobe was observed by upper abdomen CT scan, and high-density shadow was observed in the bile duct of left inferior lobe, which was significantly intensified after enhancement. The bile duct of right posterior lobe was slightly dilated. A space-occupying lesion in the bile duct of left inferior lobe was detected by upper abdomen MRI, which was unevenly intensified after enhancement. The diagnosis of intrahepatic IPNB was considered upon admission. Three-dimensional reconstruction revealed that the right anterior branch of portal vein converged into the left branch of portal vein. The bile duct of right posterior lobe converged into the left hepatic duct, composing common hepatic duct with the bile duct of right anterior lobe. The informed consent of this patient was obtained and the local ethical committee approval was received. On December 11, 2020, the patient underwent left hemihepatectomy and Spiegel lobectomy under general anesthesia. The intraoperative conditions and postoperative efficacy were observed.

The tumor was found mainly located in the left hepatic duct and invaded into the opening of bile duct of right posterior lobe during the operation. The left branch of portal vein was ligated at the distal end of the junction of right anterior branch and left branch of portal vein, and the right posterior bile duct was resected at 1 cm from the tumor, and the left hepatic duct was resected at the junction of the right anterior bile duct. The margins of 2 bile duct samples were obtained for pathological examination, and no abnormal cells were detected under microscope. After lymph node dissection of hepatoduodenal ligament, the left hepatic duct was sutured. Roux-en-Y anastomosis was performed between the bile duct of right posterior lobe and jejunum. Postoperative pathological examination indicated IPNB in the left lobe, and malignant transformation was reported adjacent to the hilum. No cancer metastasis was found in the lymph nodes of hepatoduodenal ligament, and the incisional margins of bile duct were not involved. The patient recovered well, discharged at postoperative 8 d after operation. She was followed up postoperatively till the date of submission. No tumor recurrence or metastasis was found.

Intrahepatic IPNB is a rare bile duct tumor without specific clinical manifestation and laboratory index. Imaging and pathological examination contributes to confirming the diagnosis. Preoperative three-dimensional reconstruction can identify vascular and bile duct variations, which plays a significant role in the selection of surgical regimen. Early radical resection may significantly improve the clinical prognosis.