Intrathyroidal parathyroid adenoma.

A 54-year-old woman was referred for imaging studies after presentation for palpitations and a palpable thyroid nodule. The patient underwent a dual-phase single-agent Tc-99m sestamibi scan followed later by a thyroid ultrasound at an outside hospital. The Tc-99m sestamibi scan showed a marked focus of activity separate from the thyroid bed in the inferior left neck. Thyroid ultrasound showed a dominant calcified nodule in the left lobe of the thyroid, measuring 1.3 cm, as well as 3-mm cystic lesions in both lobes of the thyroid. Also, an iodine-123 scan was performed showing a cold nodule in the left inferior thyroid. During surgery, the patient underwent a left thyroid lobectomy for an intrathyroidal parathyroid adenoma.