Rare and unique endoscopic retrograde cholangiopancreatography (ERCP) findings: insights from a 24-year single-center retrospective study

Aim: Rare conditions causing biliary obstruction, such as Fasciola hepatica infestation, SUMP syndrome, Lemmel syndrome, Wirsung duct stones, Mirizzi syndrome, and surgical clip migration, are infrequently encountered during ERCP. This study aims to analyze the clinical and demographic characteristics, diagnostic challenges, and management of these uncommon conditions in a single-center cohort. Method: This retrospective study included 6,700 patients aged 18 and older who underwent ERCP between 2000 and 2024. Patients with common bile duct stones, benign fibrosis, or malignancy were excluded, resulting in 28 cases with rare biliary pathologies. Data on clinical presentations, imaging findings, and treatment outcomes were analyzed. Results: Among the 6,700 patients, the incidence of Fasciola hepatica infestation was 0.06% (n = 4), SUMP syndrome 0.75% (n = 5), Lemmel syndrome 0.06% (n = 4), Wirsung duct stones 0.044% (n = 3), Mirizzi syndrome 0.15% (n = 10), and surgical clip migration 0.03% (n = 2). Cholangitis was the most common clinical presentation across most conditions, with notable differences in total bilirubin levels, common bile duct diameters, and associated imaging findings. All cases were successfully managed with ERCP, and no complications were observed. Conclusion: This study underscores the importance of recognizing rare biliary pathologies in patients presenting with atypical symptoms or a history of biliary surgery. Although these conditions represent a small percentage of patients undergoing ERCP, their timely diagnosis and management are crucial to preventing complications. For this reason, we are presenting these rare conditions collectively in the literature for the benefit of endoscopists.