OBJECTIVES: To describe four cases of an uncommon type of acalculous cholecystitis/cholangitis characterized by increased intraepithelial lymphocytes within the biliary epithelium. METHODS: Cases were prospectively compiled during regular surgical pathology sign-out. Clinical information was obtained from the electronic medical record and the gross appearance from the surgical pathology reports. Microscopic examination was performed with emphasis on the type, location, and distribution of the inflammatory pattern; presence of intraepithelial lymphocytes (>30 per 100 biliary cells); and presence of metaplasia and epithelial hyperplasia. Immunohistochemical stains for CD3, CD8, and IgG4 were performed in some cases. RESULTS: All patients were adults who had either biliary pain or obstructive symptoms. All gallbladders had a relatively normal gross appearance and did not contain gallstones or biliary sludge. Microscopic examination showed numerous intraepithelial lymphocytes in the biliary epithelium. The mucosa was frequently expanded by dense inflammatory cell infiltrates. The inflammatory process was more severe in the infundibulum and bile ducts than in the body of the gallbladder. The intraepithelial lymphocytes were CD3+, CD8+. IgG4+ plasma cells were absent. CONCLUSIONS: The term lymphocytic cholecystitis/cholangitis is proposed. The potential clinical implications and pathogenesis of this inflammatory pattern and the differential diagnosis with other forms of acalculous cholecystitis are discussed.
