Thyroid category 4A nodules with calcification for 17 years may be the result of benign conditions such as thyroid adenomas, or they may be the result of slow-progressing thyroid cancers such as papillary carcinomas. Thyroid category 4A nodules are of low suspicion of malignancy and have a 5% to 10% chance of being the result of a malignant tumor such as thyroid cancer, or they may be the result of a thyroid adenoma or thyroid cyst. Calcification of thyroid nodules can be seen in benign and malignant diseases. Generally, coarse, regular shape and uniform density calcifications are caused by benign diseases, while small, irregular shape and uneven density calcifications are mostly caused by malignant diseases, such as microcalcifications which are suspected to be malignant signs. Generally, 4A nodules ≤15mm can be followed up and observed, or puncture biopsy can be performed to exclude the possibility of thyroid malignant tumors. Nodules more than 15mm and adjacent to the peritoneum, laryngeal reentry nerve, trachea, etc. can be surgically resected and sent to the pathologist for pathological testing by intraoperative freezing. It is recommended that the patient consult with a specialist, combined with the specific description of the nodule in the examination report, as well as the follow-up report during the 17-year period to make a comprehensive judgment, and perform histological examination if necessary to avoid delaying the condition.