A case of recurrent embolic stroke due to non-bacterial thrombotic endocarditis despite shrinkage of lung cancer with nivolumab

Abstract

The patient was a 70-year-old man who had undergone lobectomy and was diagnosed with pulmonary pleomorphic carcinoma three years ago. The cancer spread to the lymph nodes and brain, despite use of combination chemotherapy; therefore, nivolumab was started a year before. The patient was hospitalized due to embolic ischemic stroke in the same year, but no embolic source was found in transthoracic echocardiography. He was discharged without neurological deficit and the cancer was markedly shrunk. However, 5 months later, he was readmitted with a seizure, and recurrence of ischemic stroke was observed. Transthoracic echocardiography revealed a mobile mass attached to the mitral valve and resection of the mass was performed. The mass was pathologically diagnosed as non-bacterial thrombotic endocarditis (NBTE). In this case, although nivolumab was able to control cancer progression, embolic stroke due to NBTE occurred. This indicates the need to pay attention to the NBTE as complication, even in a case in which nivolumab is effective.