Lemmel syndrome
Formal Definition
Lemmel syndrome — a clinical syndrome of recurrent biliary obstruction, abdominal pain, cholangitis, and obstructive jaundice caused by extrinsic compression of the distal common bile duct by an adjacent duodenal diverticulum (typically within 1-3 cm of the ampulla of Vater) or by periampullary disease; not caused by gallstones or malignancy but by mechanical compression of the CBD by the diverticulum itself, with or without associated inflammation or sphincter dysfunction.
How It's Used on the Ward
"Lemmel's" — recurrent biliary-type complaints (pain, jaundice, cholangitis episodes) in a patient with a periampullary duodenal diverticulum that is mechanically compressing the common bile duct; the diverticulum is the culprit, not a stone or tumor; diagnosed by ERCP or MRCP when no other cause is found.
Example
""74-year-old man with 3 episodes of biliary colic with cholangitis (fever, RUQ pain, bilirubin 4.2 mg/dL, alkaline phosphatase 380) over 18 months. Multiple ultrasounds: no gallstones, normal CBD diameter. MRCP: large duodenal diverticulum within 1 cm of the ampulla, mild CBD dilation to 12 mm, no choledocholithiasis. ERCP confirmed: diverticulum causing compression of the distal CBD. Diagnosis: Lemmel syndrome. Managed with endoscopic sphincterotomy and diverticulum-directed care, antibiotic prophylaxis for recurrent cholangitis episodes, surgical consultation for diverticulectomy in recurrent cases.""
Clinical Context
Epidemiology: present in 10-20% of adults undergoing ERCP (incidental finding), but Lemmel syndrome (symptomatic) is much less common. Demographic: older adults, slight male predominance. Pathophysiology: periampullary diverticulum (PAD) or juxtapapillary diverticulum mechanically compresses the distal CBD; may also cause functional obstruction through sphincter of Oddi dysfunction; chronic inflammation around diverticulum affects biliary drainage. Diagnostic workup: MRCP or ERCP to identify PAD + CBD compression, rule out stones (CBD stones vs pseudolithiasis — Lemmel can produce biliary sludge/mimic stones with papilla dysfunction), rule out malignancy (ampullary, pancreatic head). Treatment: endoscopic sphincterotomy to relieve CBD obstruction; surgical diverticulectomy for recurrent or refractory cases; antibiotics for cholangitis episodes. Differential: choledocholithiasis (most common cause of similar symptoms), ampullary stenosis, periampullary malignancy — Lemmel is a diagnosis of exclusion once these are excluded. Sometimes called "juxtapapillary or periampullary diverticulum syndrome."