Lemmel syndrome: A single-center cohort and diagnostic considerations.

Objective: Lemmel syndrome is an uncommon cause of obstructive jaundice resulting from extrinsic compression of the common bile duct by a periampullary duodenal diverticulum (PAD) in the absence of choledocholithiasis. Due to its non-specific clinical presentation, diagnosis may be delayed or misinterpreted. Material and Methods: A retrospective review was conducted on 12 patients diagnosed with Lemmel syndrome at a single tertiary center between 2022 and 2024. Demographic characteristics, clinical presentation, laboratory findings, imaging modalities [ultrasonography (USG), computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP)], endoscopic interventions, and outcomes were analyzed descriptively. Results: The cohort included 12 patients with a mean age of 70±9 years. All patients presented with clinical or biochemical evidence of obstructive jaundice. USG frequently failed to establish the diagnosis, whereas CT and particularly MRCP demonstrated the anatomical relationship between the PAD and the biliary tree. Endoscopic retrograde cholangiopancreatography served both diagnostic and therapeutic purposes, with biliary stenting performed when indicated. Most patients improved with conservative and/or endoscopic management. Conclusion: Lemmel syndrome should be considered in elderly patients with unexplained obstructive jaundice. Cross-sectional imaging, particularly MRCP, plays a key role in diagnosis, while endoscopic intervention remains central to management.