The diagnosis of drug induced liver injury (DILI) has caused significant challenges for the pathologist, mainly due to the fact that histopathological features of DILI mimic all primary hepatic and biliary diseases, and do not display any peculiar changes related to DILI. Although the pathologist needs to confirm the clinician that the observed hepatic changes are compatible with DILI in any patient of suspected DILI who underwent liver biopsy, this information is less useful as it lacks specificity. Instead of following this, the pathologist should evaluate liver biopsies blindly, without knowledge of prior treatment by drugs, which can lead to detailed description of the histological findings, correlated with suggestions for potential causes of these hepatic changes. This leaves the formulation of diagnosis up to the physician to re-examine carefully the differential diagnoses. 

Currently, evidences suggest that liver histology does not have much influence in establishing the diagnosis of DILI with the desired certainty. Similar uncertainty can be seen in herb induced liver injury (HILI). 

Therefore, clinical and structured causality determination are more successful approaches in comparison to liver histology in establishing a correct diagnoses of DILI and HILI, as liver biopsy is an invasive procedure with a low complication rate. However, liver biopsy can be considered as a final diagnostic approach in rare cases of diagnostic uncertainty regarding alternative causes.

Source: Teschke R, Frenzel C. Drug induced liver injury: do we still need a routine liver biopsy for diagnosis today? Ann Hepatol. 2013 Jan-2014 Feb;13(1):121-6. PMID: 24378275.