Histology of amiodarone-induced liver injury revisited: A retrospective morphologic analysis

Amiodarone-induced liver injury (AILI) is a known risk of amiodarone therapy, with presentations ranging from asymptomatic aminotransferase elevations to severe or fatal hepatitis and cirrhosis. Due to limited understanding of its histopathologic features, we conducted a retrospective cross-sectional re-analysis of liver biopsy samples from patients on amiodarone from two centers. Of the 48 liver biopsy samples, 42 (87%) exhibited histologic evidence of AILI. All patients showed minimal or mild macrovesicular steatosis. Ballooned hepatocytes were observed in 36 cases (86%), with 25 (69%) displaying a periportal distribution, 8 (22%) centrilobular, and 3 (8%) panacinar in distribution. Mallory-Denk bodies were found in 36 samples (76%)-18 (50%) were numerous and 18 (50%) multiple. Cholestasis was present in 10 patients, 7 (70%) of whom died. In contrast, 10 (31%) of the 32 patients without cholestasis died. This represents a significantly increased mortality risk for patients with AILI and cholestasis (p = 0.03). While AILI shares features with the more generally known metabolic dysfunction-associated steatotic liver disease, our findings indicate that a prominence of periportal distribution of ballooned hepatocytes and Mallory-Denk bodies despite a minimum of macrovesicular steatosis are characteristic of AILI. Furthermore, cholestasis in biopsy samples may suggest a poorer prognosis in patients on amiodarone.