A Curious Case of Intraductal Papillary Mucinous Neoplasm of the Bile Duct Presenting With Cholangitis.

Intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) belongs to a group of biliary disorders that are premalignant lesions and have a relatively low incidence. We describe a case of a patient with IPMN-B who presented unusually with cholangitis and underwent surgical resection as a definitive treatment. The patient was a 65-year-old male who presented with a six-month history of recurrent right upper abdominal pain and loss of appetite, with a recent history of jaundice. Blood investigations showed leukocytosis with altered liver function test, with elevated bilirubin and liver enzymes. Ultrasound of the abdomen showed features suggestive of a cystic lesion in the left lobe of the liver. Further evaluation with a contrast MRI with magnetic resonance cholangiopancreatography (MRCP) showed a cystic lesion measuring 4x4 cm with mural lesions and biliary communication to the left hepatic duct. Serum CA19-9 was within normal limits (2 U/mL). Patient underwent endoscopic retrograde cholangiopancreatography (ERCP) in view of cholangitis and later had surgery in the form of left lateral sectionectomy with intraoperative cholangioscopy. The postoperative period was uneventful, and the patient was discharged on the fourth postoperative day. The histopathology report showed features suggestive of intraductal papillary mucinous neoplasm of the biliary tract with low-grade dysplasia. Patient was followed up at three months and was found to be without any complications. IPMN-B is a rare disease, and patients presenting with cholangitis are rather uncommon. Physicians need to be aware of such cases, as their management is different from cholangitis due to other causes, which are frequently encountered in clinical practice. IPMN-B requires a detailed imaging workup and definitive surgical resection due to its high risk of malignant transformation.