Liver biopsy in a patient with checkpoint inhibitor induced hepatitis. Findings demonstrate hepatic parenchyma with mild portal inflammation, interlobular bile duct injury, and associated ductular reaction. The portal tracts contain, but are not significantly expanded by, a mixed inflammatory infiltrate comprised of lymphocytes, histiocytes, and scattered eosinophils.  This inflammation is associated with interlobular bile duct injury characterized by intraepithelial lymphocytes and neutrophils, and a ductular reaction with accompanying neutrophils.