Thrombosis in an Internal Jugular Vein and an Upper Limb Deep Vein Treated with Edoxaban

A 45-year-old man complained of swelling of the left side of his neck and left upper limb. Ultrasonography and enhanced computed tomography (CT) revealed thrombosis of the left internal jugular, subclavian, and brachiocephalic vein. Based on various examinations, the patient was diagnosed with idiopathic venous thrombosis early in his clinical course. There were no findings to suggest malignancy or abnormal coagulability. However, two months after the start of treatment, the patient was diagnosed with gastric cancer. Despite the presence of Trousseau syndrome, treatment with edoxaban (an oral anticoagulant), reduced the swelling dramatically without any bleeding complications.