TG and metastatic malignant neoplasm in the lymph nodes: However, for patients with no evidence of lymph node metastasis by preoperative ultrasound and Tg evaluation, who had received thyroid and/or lymph node dissection, and were followed up regularly with ultrasound and Tg after surgery, 77% still showed abnormalities within one year after the surgery [7], which may be related to postoperative occult lymph node metastasis.