Incidental detection of a malignant hurthle cell carcinoma by Tc-99m sestamibi cardiac imaging.

A 60-year-old man reported chest pain and shortness of breath. His medical history was negative for myocardial infarction but positive for "mini strokes" and type 2 diabetes mellitus. Tc-99m sestamibi cardiac imaging revealed an abnormal focus of increased activity in the left lobe of the thyroid. Although no cardiac abnormalities were found, a I-123 thyroid scan subsequently showed a solitary hypofunctioning nodule involving the middle and inferior aspects of the left lobe of the thyroid, which fine-needle aspiration proved was a Hurthle cell carcinoma.