Is it really dangerous to find calcification on thyroid examination? Calcification is less frequent in benign thyroid lesions, about 6%~14%, most of which are coarse calcifications, while the incidence of microcalcifications is lower. The total calcification rate of malignant thyroid tumors is 37%~75.7%, of which the incidence of microcalcifications is 55%~68%, which is higher than the incidence of coarse calcifications, in contrast to benign lesions. Table 1 shows the calcification rates of some thyroid lesions reported in the literature. The reasons for this may be: (1) Ultrasonography is highly influenced by operator subjectivity and often results in missed calcifications of the thyroid gland because they are too small or hidden behind coarse calcifications and fibrotic acoustic shadows. (2) Because calcified nodules in thyroid cancer are usually small, it is difficult to pass the calcified foci in paraffin sections precisely, and because calcified foci are not required for pathologic characterization, they are usually not detected at a high rate unless they are prospectively studied or specifically brought to the attention of the pathologist. Clinical significance About 25% of thyroid nodules in general show calcified shadows, while 50% to 62.5% of thyroid cancers have calcifications. It is generally believed that the coarser the calcification particles, the better the differentiation of the cancerous tissue. The characteristics of calcification shadows may be related to the classification of cancer as follows: (1) sandy calcification, which is almost common to malignant thyroid tumors, is often a characteristic manifestation of papillary carcinoma. (2) About 10%-20% of the coarse calcified images are carcinoma, among which follicular adenocarcinoma accounts for a large proportion. (â‘¢Medullary carcinoma is often mixed with coarse granules and sand-like calcifications. â‘£Generally, calcified images of benign thyroid tumors are more dense with clear margins, while malignant tumors have faint and blurred shadows. The above is an introduction to the clinical significance of calcification of thyroid nodules. Through the above description, we can see that the characteristics of calcified shadows of thyroid nodules may be related to cancer classification. Patients must go to a professional hospital when doing the diagnosis of calcification of thyroid nodules to avoid any missed diagnosis.