What is Lemmel syndrome?

What is Lemmel Syndrome?

Lemmel syndrome is a rare cause of obstructive jaundice resulting from mechanical compression of the common bile duct by a periampullary duodenal diverticulum, occurring in the absence of choledocholithiasis or pancreaticobiliary tumors. 1, 2

Clinical Presentation and Epidemiology

• Periampullary duodenal diverticula are found incidentally in approximately 22-23% of the general population, but less than 10% of these individuals develop symptomatic obstruction 1, 3
• Only about 5% of duodenal diverticula lead to complications such as biliary or pancreatic duct obstruction 3
• Patients typically present with the classic triad of obstructive jaundice, right upper quadrant or flank pain, and elevated liver enzymes (bilirubins, transaminases) and/or pancreatic enzymes 1
• The syndrome is frequently misdiagnosed due to the absence of specific pathognomonic signs and recurrent presentations that mimic choledocholithiasis 2, 4

Pathophysiology

The mechanism involves a juxtapapillary duodenal diverticulum that causes mechanical compression of the intrapancreatic portion of the common bile duct, resulting in upstream dilatation of both extra- and intrahepatic biliary ducts 4, 3. This compression occurs without the presence of stones or mass lesions, making it a diagnosis of exclusion 2.

Diagnostic Approach

Magnetic resonance cholangiopancreatography (MRCP) is the imaging modality of choice for confirming the diagnosis of Lemmel syndrome. 2, 3

Imaging Algorithm:

• Initial evaluation: Ultrasonography can identify upstream dilatation of biliary ducts but may miss the causative diverticulum 4
• Definitive diagnosis: CT with oral contrast or MRCP demonstrates the periampullary diverticulum compressing the common bile duct and reveals dilated bile ducts without calculi or mass lesions 4, 3
• Endoscopic confirmation: Gastroduodenoscopy can directly visualize the periampullary diverticulum 2

Critical Diagnostic Pitfall:

Lemmel syndrome is underreported and frequently missed because clinicians focus on more common causes of obstructive jaundice (stones, tumors) and fail to recognize structural abnormalities on imaging 2, 4. Always consider Lemmel syndrome when patients present with recurrent episodes of obstructive jaundice with dilated bile ducts but no identifiable stones or masses on imaging. 3, 5

Management Strategy

Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy is the first-line treatment for Lemmel syndrome. 1, 2, 3

Treatment Algorithm:

1. Primary approach: ERCP with endoscopic sphincterotomy to relieve the obstruction 2, 3
2. Adjunctive procedures: Biliary stent placement may be performed during ERCP for sustained relief 3
3. Surgical intervention: Reserved for cases where ERCP fails or is technically not feasible; options include surgical biliary derivation or laparoscopic cholecystectomy if concurrent gallbladder pathology exists 2, 3

Complications

• Ascending cholangitis is a serious complication that can occur when biliary obstruction leads to bacterial infection, requiring urgent intervention 2
• Gastric outlet obstruction has been reported in rare cases, though this is not a typical complication 5
• Pancreatitis can develop from pancreatic duct compression by the diverticulum 3

Key Clinical Pearls

Suspect Lemmel syndrome in any patient with recurrent right upper quadrant pain and obstructive jaundice who has undergone multiple emergency room visits without identification of stones or tumors. 4, 5 The diagnosis requires a high index of suspicion and appropriate advanced imaging, as conventional ultrasound alone is insufficient for definitive diagnosis 4.