Thyroid grade 4a, or thyroid nodule 4a, is a low-grade suspicious malignant nodule with the potential for a benign nodule. The TIRADS classification of thyroid nodules is an ultrasound classification of thyroid nodules, which is a method of classifying and evaluating the ultrasound characteristics of the nodules during thyroid ultrasound examinations and assessing the risk of malignancy of the nodules.The TIRADS classification is divided into a total of 6 levels. Of these, 4a represents low suspicion of malignancy, with a malignancy rate of 2% to 10%, and a relatively high likelihood of benignity for thyroid nodules 4a. For 4a thyroid nodules, if the nodule is large, cytologic puncture is feasible to clarify the diagnosis. If the nodule is determined to be malignant, or if the nodule is too large and presents with obvious compression symptoms, surgical treatment is feasible. When thyroid nodules appear, it is recommended to consult a doctor in time and standardize the treatment.