Abstract
Lenvatinib, a multi-kinase inhibitor, has shown promising activity in unresectable thymic carcinoma, but long-term real-world data are scarce. We describe a 72-year-old woman with Masaoka stage IVb thymic squamous cell carcinoma who experienced disease progression after ADOC chemotherapy and multiple courses of thoracic radiotherapy. Lenvatinib was initiated at 24 mg/day and reduced to 8 mg/day because of hypertension, hemoptysis, and hypothyroidism. The patient achieved 23 months of disease stabilization before sudden death at home. Postmortem imaging suggested acute exacerbation of interstitial pneumonia. This case highlights the potential of lenvatinib to achieve prolonged disease control even at reduced doses and underscores the need for careful pulmonary monitoring in patients with prior thoracic irradiation.