Hajime Takeuchi1, Toru Kaneko1, Toshikazu Otsuka1, Kumiko Tahara1, Tadashi Motoori2, Makoto Ohbu3, Masaya Oda4, Hiroaki Yokomori11Department of Internal Medicine; 2Division of Pathology, Kitasato Medical Center Hospital, Kitasato University, Saitama; 3Department of Pathology, School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa; 4Department of Internal Medicine, Saitama Social Insurance Hospital, Saitama; 5Organized Center of Clinical Medicine, International University of Health and Welfare, Sanno Hospital, Tokyo, JapanAbstract: This report describes a case showing histologic features of acute cholangitis with an over-the-counter drug. A 48-year-old woman was diagnosed with general malaise and progressive jaundice. A thorough review of her medical history revealed that the patient had taken an over-the-counter drug, Pabron Gold®, which she had used previously, that may have caused liver injury. Laboratory investigations revealed jaundice and liver dysfunction. Endoscopic retrograde cholangiography detected no extrahepatic biliary duct dilatation or stones. Liver biopsy indicated acute cholangitis involving neutrophils and eosinophils. Electron microscopy revealed fragmented nuclei, indicating that the degenerative bile duct-related epithelial cells were in an apoptotic process.Keywords: liver injury, over-the-counter drug, histologic features, acute cholangitis, electron microscopy, Pabron Gold