The clinical manifestations of TMC are basically the same as those of thyroid cancer, except that the lesions are small and often difficult to detect without careful examination. 1. Tiny nodules can be palpated in the thyroid gland with hard texture, good mobility and no pressure pain. Among the 867 cases of TMC reported by Noguchi, only 23 cases (2.7%) had palpable nodules in the thyroid gland. In the case of combined multinodular goiter, attention should be paid to the presence of small, hard nodules among the many nodules of varying sizes. The texture of these nodules differs from that of the surrounding goiter nodules. During physical examination, both lobes of the gland should be carefully palpated. Do not pay attention to the thyroid lobe on the obvious side of the nodule and neglect to examine the contralateral lobe where the nodule is not obvious. 3. Metastasis to the lymph nodes in the neck often occurs in TMC. The literature reports that the incidence of cervical lymph node metastasis in TMC ranges from 2.0% to 43%, and in some cases, enlargement of cervical lymph nodes is the earliest clinical manifestation of TMC. Tumor development within the lymph nodes may be rapid and cystic necrosis and lymph node degeneration may occur. Many cervical lymph node metastases may be misdiagnosed as cervical cystic lesions or bronchial cysts. 4. Distant metastasis, such as spine, bone and lung metastasis, may occur, but the incidence is extremely low. In some cases, bone metastases may become the first manifestation. Because the primary nodes of TMC are small, clinical palpation is difficult, and many cases are diagnosed only after the presence of lymph node metastases, distant metastases, or puncture biopsy of the metastases, or excisional biopsy. In more cases, the diagnosis may be confirmed by frozen section examination of suspected tiny cancer nodules removed during surgery for other thyroid diseases, or postoperative paraffin section examination. Because of the small size of cancer nodules, the diagnostic rate of imaging is low in all cases.