Recurrent Drug-Induced Pneumothorax Associated With Lenvatinib: A Case Report.

We present a patient with recurrent pneumothorax induced by lenvatinib, used for the treatment of thymic carcinoma. A 76-year-old Japanese man, who is a current smoker, was diagnosed with thymic carcinoma with pulmonary metastasis and pleural dissemination. Lenvatinib was initiated as third-line chemotherapy in April 2022. He was subsequently admitted to our hospital in August and October 2023 for recurrent left-sided pneumothorax. Following the second left pneumothorax, lenvatinib was discontinued, and he has remained free of pneumothorax for over a year. Clinicians should be aware of the potential adverse effects of lenvatinib in patients with pulmonary metastasis or pleural dissemination.