Abstract
BACKGROUND: Anastrozole, an aromatase inhibitor (AI), has been used extensively for the treatment of estrogen receptor-positive breast cancer. Autoimmune hepatitis (AIH) is an extremely rare but serious complication of anastrozole treatment. CASE DESCRIPTION: We present the case of an 81-year-old female who presented with significantly elevated liver function test (LFTs) results 8 months after the initiation of anastrozole for early-stage breast cancer. Serological and liver biopsy findings were consistent with AIH. Discontinuation of anastrozole, along with a short course of steroids, resulted in rapid clinical improvement and normalization of both LFTs and autoantibodies. CONCLUSION: Clinicians should be aware of drug-induced AIH as a rare but life-threatening complication of anastrozole and potentially other aromatase inhibitors.