Thyroid nodules with calcification are often seen in physical examination reports, and people are afraid of “calcification”. In fact, there are many types of calcifications, and benign tumors can also have calcifications. The calcifications can be divided into the following categories according to the morphology of the calcifications: 1. small calcifications: gravel-like or pinpoint-like multiple calcifications, which have a high possibility of malignancy, the mechanism of which is unknown and may be caused by the metabolism of the tumor cells or the deposition of calcium salts after necrosis. Biopsy is needed to clarify or surgery. 2. Calcification of the cystic wall of thyroid cysts: mostly benign, which occurs due to the deposition of calcium salts in the cystic fluid. 3. Punctate calcification: mostly seen in colloid accumulation nodules, with good nodule morphology, common in young people. 4, coarse calcification: multiple coarse calcifications are more likely to be malignant, and single coarse calcifications are more often benign. Biopsy is required for clarification or surgery. 5. Mass calcification: The entire nodule is mostly filled with calcification, mostly fibrotic calcification of the thyroid nodule, which is difficult to distinguish between benign and malignant. Biopsy often fails because the tissue is too hard. 6, cystic solid mass solid part with calcification: especially the cyst with solid part papillary projection, solid part of the calcification is also considered malignant possibility.