[A Case of Liver Abscess during Treatment for Abemaciclib-Induced Interstitial Lung Disease].

The patient was a 64-year-old woman. The patient was operated for left breast cancer(pT2N0M0, stage ⅡA, Luminal A). Eight years after surgery, CT findings revealed lung metastasis in the S8 and S9 areas of the left lung. The patient was treated with a combination of abemaciclib and letrozole, which resulted in a partial response(PR). One year after treatment, the lung metastases remained small, but multiple interstitial shadows appeared in both lower lung fields. The patient was diagnosed with drug-induced interstitial lung disease(Grade 1), and abemaciclib withdrawal and steroid therapy were initiated. After 3 months of treatment with prednisolone at 30 mg/day, the interstitial shadows tended to improve on CT, but a liver abscess was found in the S8 area of the right lobe of the liver. Prednisolone was tapered and abemaciclib was resumed at a dose of 200 mg/day, resulting in scarring of the lung injury and resolution of the liver abscess. The patient's PR was maintained for 18 months after relapse. We report a case of liver abscess during treatment of abemaciclib-induced interstitial lung disease.