Thyroid nodule category 4b can be withheld from surgery if it is confirmed benign by fine needle aspiration, if the biopsy result is malignant do not want to operate may have adverse consequences such as tumor metastasis. Thyroid nodule is a common disease, which is a confined mass in the thyroid tissue. Thyroid ultrasound can grade the risk of malignancy of thyroid nodules (grades 0 to 6). category 4b has a 10% to 50% risk of malignancy and requires a fine needle aspiration biopsy to clarify the benign or malignant nature of the nodule. If the nature of the nodule is benign, it can be followed up regularly with repeat thyroid ultrasound to observe changes in the thyroid nodule. If the nodule is malignant, surgery is needed. If you do not want to have surgery, you may have tumor metastasis, which can worsen your condition and endanger your life. Thyroid category 4b nodules should be seen promptly in the hospital and treated under the guidance of the doctor.