Intraductal papillary neoplasm of the bile duct: A case report of a rare tumor with a brief review of literature

Introduction and importance: Intraductal papillary neoplasm of the bile duct (IPNB) is a rare neoplasm, mostly found in patients from far Eastern areas where hepatolithiasis and clonorchiasis are endemic. Very few cases are reported from India. Case presentation: We present a case of recurrent cholangitis in a 59 -year -old male, initially suspected to have IPNB based on preoperative imaging. Confirmation occurred intraoperatively, with mucin-filled bile ducts and papillary lesions in the resected hepatic duct. Treatment included left hepatectomy, extrahepatic bile duct excision, and Roux-en-Y hepaticojejunostomy. Histopathology indicated invasive pancreatobiliary-type IPNB with clear margins. The patient experienced post-hepatectomy hepatic insufficiency and superficial incisional surgical site wound infection, managed conservatively. Discharge occurred on postoperative day 21, with satisfactory recovery at the 16-month follow-up. Clinical discussion: IPNB is recognized as the biliary equivalent of intraductal papillary mucinous neoplasm, as these two conditions exhibit multiple commonalities in terms of clinical and histopathological characteristics. The unique aspect of our case lies in the intricacies associated with its diagnosis. Initially, imaging modalities did not yield a definitive characterization of the lesion. Notably, the endoscopist misinterpreted mucin expression emanating from the papilla as purulent material, primarily due to the patient's concurrent cholangitis. Subsequent repetitions of both CT scan and MRI provided some valuable insights that contributed to the diagnostic clarity of the IPNB. Conclusion: In cases of symptoms like biliary obstruction with bile duct dilation, wall nodules, papillary/solidcystic masses, and upstream-downstream dilation, IPNB should be considered. Striving for R0 resection is crucial for enhanced long-term patient survival.