Multiple organ infarction caused by aortic thrombus in a lung cancer patient with the BRAF mutation

A 72-year-old male patient with advanced lung adenocarcinoma harboring a BRAF mutation had received treatment with a BRAF inhibitor and a MEK inhibitor. Treatment was ceased after 40 days because of disease progression. Twenty-four days after treatment cessation, the man was referred to our hospital with worsening abdominal and back pain over 2 weeks. Computed tomography revealed a massive thrombus in the descending aorta, bilateral kidney infarction, splenic infarction, and intestinal enlargement due to ileus. He was diagnosed with multiple organ infarction caused by arterial thromboembolism. Tumors harboring BRAF mutations and BRAF/MEK inhibitor therapy both have the potential to increase thrombosis risk, and were therefore thought to be associated with the occurrence of aortic thrombosis.