I had total thyroidectomy. hypodense nodule right thyroid bed 11mm by 9mm. significance uncertain. nonspecific lymph nodes. could this be cancerous?

Possibly: The total thyroidectomy was performed for a lesion in the thyroid that was not a goiter. That signifies that the lesion removed by the procedure had a potential for malignancy. Frozen section usually performed would inform surgeon of pathology and as such if Ca, a lymph node dissection would have been performed. If no Ca then any lesion in the bed is benign but should be followed.