Case report: bilateral massive internal jugular vein thrombosis in carcinoma of the thyroid: CT evaluation.

Superior vena cava syndrome, an uncommon manifestation of carcinoma of the thyroid, is usually due to retrosternal extension of the growth. Rarely, however, there may be direct tumour extension into the great veins of the neck, which may cause sudden death. Only eight such cases have been reported in the English literature. The case reported by us is the first to be documented by computed tomography. Patients with carcinoma of the thyroid with the superior vena cava syndrome should undergo computed tomography to differentiate external compression due to goitre from intraluminal tumour.