External Jugular Vein Thrombosis as a Sign of Metastatic Breast Cancer

External jugular vein thrombosis is a rare vascular event which may lead fatal complication such as sepsis and pulmonary embolism. Its relation to the visceral solid tumor as an etiologic factor has been established well. Although external jugular vein thrombosis may be seen in malignancy, it is unusual to see as a sign of breast cancer. Most of the external jugular vein thrombosis occurs secondary to compression of the vein. Vascular thrombosis due to hypercoagulability is known as Trousseau syndrome. Herein, we present a case of metastatic breast cancer which presented with external jugular vein thrombosis; Trousseau syndrome.