According to the recent American Thyroid Association guidelines [16], an upper chest and neck CT scan with IV contrast should be obtained when: 1) neck US is inadequate in visualizing possible local nodal disease (high Tg, negative neck US, and RAI imaging); 2) US is not able to delineate the disease completely, as in the case of bulky recurrent nodal disease; or 3) evaluation of possible recurrent invasive disease is needed (Figs. 7, 8 and 9). The gene discussed is TG; the disease is glycogen storage disease VI.