Intraductal papillary neoplasm of the bile duct: a clinical analysis of 62 cases and evaluation of prognostic factors

To investigate the clinicopathological characteristics of intraductal papillary neoplasm of the bile duct (IPNB) and the prognostic factors influencing survival in patients with malignant IPNB. A retrospective analysis was performed on the clinicopathological data and postoperative follow-up records of 62 IPNB patients who underwent surgical treatment at the First Affiliated Hospital of Army Medical University from September 2010 to March 2021. Clinical and pathological characteristics were compared among patients with different histopathological grades (e.g., low-grade vs. high-grade intraepithelial neoplasia) and anatomical subtypes (e.g., intrahepatic, extrahepatic, and diffuse types). Prognostic factors affecting survival in malignant IPNB cases were analyzed using multivariate statistical methods. Based on pathological findings, the 62 IPNB patients were categorized into three groups: low-grade intraepithelial neoplasia (LGIN group, n = 20), high-grade intraepithelial neoplasia (HGIN group, n = 23), and associated invasive carcinoma (IC group, n = 19). The LGIN group exhibited a significantly lower proportion of patients with elevated CA19-9 (> 37 U/mL) compared to the other two groups (p = 0.009). No statistically significant differences were observed in demographic or perioperative parameters among the three groups. Patients in the HGIN and IC groups demonstrated inferior overall survival rates compared to the LGIN group (p = 0.007). After merging HGIN and IC groups into a malignant cohort, the malignant group showed significantly worse overall survival than the LGIN group (p = 0.002). Multivariate Cox regression analysis identified postoperative recurrence, abdominal pain, and non-radical surgery as independent predictors of poor prognosis in the malignant group (p < 0.05). According to the modified anatomical classification system, the 62 patients were stratified into intrahepatic (n = 43), extrahepatic (n = 15), and diffuse (n = 4) subtypes. The intrahepatic group had a significantly higher rate of radical resection compared to the extrahepatic and diffuse groups (p = 0.006). Surgical approaches differed markedly among subtypes: intrahepatic cases predominantly underwent partial hepatectomy (p < 0.001), whereas extrahepatic cases more frequently required extrahepatic bile duct resection (p < 0.001). The modified anatomical classification system provides partial guidance for determining the optimal surgical resection extent in IPNB patients. Radical resection demonstrates superior prognosis compared to palliative treatment. Postoperative recurrence, abdominal pain, and non-radical surgery are identified as independent risk factors for adverse prognosis in malignant IPNB cases. In patients with suspected IPNB, radical resection should be pursued aggressively, especially in those presenting with abdominal pain or elevated CA19-9.