Unanticipated discovery: incidental encounter with fasciola hepatica during ERCP - a case report.

Introduction and Importance: Fasciola hepatica (FH) is a rare parasitic infection in humans. Its incidental detection during endoscopic retrograde cholangiopancreatography (ERCP) is exceptionally uncommon. This case underscores the importance of considering parasitic infections, even in low-endemicity regions, and the potential implications of dietary and environmental factors in disease transmission. Case Presentation: The authors present a case of a 31-year-old female from Dhading, Nepal, who underwent ERCP for suspected biliary stone. The patient had been experiencing recurring, nonradiating, burning epigastric pain for 5 to 7 years, which had recently intensified. Previous evaluations, including abdominal ultrasonography, CT, and MRI, revealed a dilation within the common bile duct and an obstruction in the biliary system. Clinical Discussion: During ERCP, cholangiography revealed mildly dilated extra and intrahepatic bile ducts with irregular filling defects in the common hepatic duct. Sphincterotomy was performed, followed by the extraction of multiple FH worms. A 7 Fr 7 cm double pigtail plastic stent was placed with a good flow of bile. However, the patient experienced anaphylaxis during the procedure, necessitating swift and tailored administration of appropriate medications to ensure effective management and stabilization. The patient was closely monitored in the ICU postprocedure. Conclusion: After careful monitoring and treatment, the patient fully recovered. The unexpected discovery of FH during ERCP is extremely rare. Early recognition and appropriate management of such incidental findings are crucial to ensuring optimal patient outcomes.