This study reveals key clinicopathologic insights into perihilar intraductal papillary neoplasms (IPNBs) and their association with invasive carcinoma, informing surgical management.

• Of 27 cases, 21 had associated invasive carcinoma, highlighting the high incidence of malignancy in patients.
• Median tumor size was 2.8 cm, with invasive tumor size averaging 1.2 cm.

Understanding these characteristics can improve patient selection for surgical intervention and inform prognosis discussions.

• Genetic alterations linked to significant pathways could guide future targeted therapies.