Concurrent follicular cholangitis and follicular cholecystitis with an isolated elevation of CA19-9.

Follicular cholangitis is a rare cause of bile duct inflammation and stenosis, mimicking stricturing malignancies such as cholangiocarcinoma. This condition is considered distinct from follicular cholecystitis, which involves chronic inflammatory and lymphoplasmacytic changes in the gallbladder. We present a case of a woman in her 70s who was incidentally found to have an intrahepatic bile duct stricture in the left lobe of the liver. After surgical management, she was found to have concurrent follicular cholangitis and follicular cholecystitis. This case highlights the similar histopathological features and overlap of the conditions.