Unexpected Complication of a Multinodular Goitre

Multinodular goitre is the most common thyroid gland disorder. It can cause hyperthyroidism and mechanical complaints such as tracheal compression or dysphagia. We report a unique case of a patient with a toxic multinodular goitre presenting with a deep venous thrombosis of the left arm due to direct local compression of blood flow. LEARNING POINTS: Multinodular goitre can cause deep venous thrombosis of the upper extremity due to local compression of blood flow. Hyperthyroidism causes a hypercoagulable and hypofibrinolytic state which, if left untreated, is a risk factor for venous thrombosis. A diagnostic algorithm combining the Constans clinical score, D-dimer testing and, when indicated, ultrasonography is a safely and effectively approach for investigating suspected deep venous thrombosis of the upper extremity.