Letrozole-induced autoimmune hepatitis presenting with decompensated cirrhosis in an elderly woman: a case report

Abstract

Autoimmune hepatitis (AIH) is a chronic immune-mediated inflammatory liver disease characterized by progressive hepatocellular injury, elevated autoantibodies, and hypergammaglobulinemia. Drug-induced autoimmune hepatitis (DIAIH) is a rare clinical entity that closely resembles idiopathic autoimmune hepatitis in both clinical presentation and histopathological findings, making diagnosis challenging. Among the implicated medications, letrozole-associated autoimmune hepatitis has been reported only rarely in the literature. Herein this case reports the case of a 64-year-old female receiving letrozole therapy for breast carcinoma who presented with features of hepatic encephalopathy and worsening liver dysfunction. Laboratory investigations demonstrated markedly elevated liver enzymes, raised immunoglobulin G (IgG) levels, and positive anti-smooth muscle antibodies (ASMA). Radiological evaluation suggested chronic liver disease, while liver biopsy revealed interface hepatitis with established cirrhotic changes, findings consistent with autoimmune hepatitis. After exclusion of other causes of liver injury, a diagnosis of letrozole-induced autoimmune hepatitis was considered. Early recognition, prompt withdrawal of the offending drug, and timely initiation of appropriate management are essential to prevent progression to advanced liver disease and liver failure.