Ectopic thyroid glands generally occur in the midline as a result of abnormal median migration, and their presence lateral to the midline is extremly rare. We report a 83-year-old male with anaplastic carcinoma admix papillary carcinoma in the extrathyroid area. We suspected left lateral neck metastasis on preoperative fine needle aspiration result and computed tomography. the patient underwent total thyroidectomy and left selective neck dissection(level II, III, IV, V). The patient was diagnosed as having an ectopic thyroid gland on the lateral neck with anaplastic carcinoma admix papillry carcinoma. The patient is alive without incident of tumor recurrence at 5month after surgery and radiotherapy.