Histopathological challenges in suspected drug-induced liver injury.

When a patient with suspected drug-induced liver injury (DILI) undergoes liver biopsy, the pathologist is confronted with two major challenges. The first and most important is to establish the pattern(s) of injury which are present. Patterns of injury represent stereotypical responses of an organ to injury and relate to specific aetiologies of liver damage. The pattern of injury and the histological details of that injury can then be analysed with respect to the patient's intercurrent diseases and medication history. The specific expertise of the pathologist can be used to weigh the prospect of DILI against the likelihood of other explanations of injury. The second challenge is to characterize specific types of injury and the severity of injury, both of which may have importance for clinical decision-making and prognosis. The pathologist's report should convey both an accurate description of the pathology as well its interpretation.