The main cause of medullary thyroid carcinoma is mutation of the RET proto-oncogene. When symptoms such as unilateral or bilateral thyroid lumps, dyspnea, dysphagia, hoarseness, hand and foot twitching, carcinoid syndrome, etc. occur, medullary thyroid cancer should be alerted. Women between the ages of 30 and 60 with a family history of parathyroid and adrenal tumors are vulnerable to medullary thyroid cancer and should pay attention to prevention. Medullary thyroid carcinoma is not actually a thyroid cancer, it is derived from calcitonin-secreting parafollicular thyroid cells (also known as C cells), which are neuroendocrine cells and have nothing to do with thyroid follicular cells. Causes of disease Pathogenesis 1. The main cause of MTC is mutation of the RET proto-oncogene; 2. About 95% of hereditary MTC and 70% of sporadic MTC are caused by mutation of the RET proto-oncogene located at 10q11.2. Pathogenesis 1. The main pathogenesis is that mutations in the RET proto-oncogene lead to changes in protein conformation in the inner and outer regions of thyroid C cells, which in turn induce excessive cell proliferation and carcinogenesis; 2. The RET proto-oncogene is located on the long arm of chromosome 10 and contains 21 exons, encoding a transmembrane protein belonging to the tyrosine kinase receptor superfamily; 3. These mutations can lead to changes in protein conformation in the extracellular and intracellular regions, respectively, and such conformational changes can enhance the transforming ability of RET, stimulate tyrosine kinase autophosphorylation, and induce excessive cell proliferation leading to carcinogenesis. Clinical manifestations of medullary thyroid carcinoma: 1. unilateral or bilateral thyroid mass: SMTC mostly presents as a single thyroid tumor; hereditary MTC mostly presents bilateral multicenter thyroid tumors; 2. dyspnea and dysphagia: caused by large masses compressing the trachea and esophagus; 3. masses in the lateral cervical region: due to enlarged regional metastatic lymph nodes; common metastatic sites include the central group of the neck and lateral lymph nodes The rate of lymph node metastasis is more than 75% in MTC patients whose lumps can be palpated by clinicians; 4. hoarseness: caused by tumor invasion of the laryngeal nerve; 5. hand and foot convulsions, caused by lowering of blood calcium due to calcitonin; 6. facial flushing, palpitation, diarrhea, wasting and other carcinoid syndrome: easily seen in patients with extensive liver metastases, caused by various peptides and peptide hormones secreted by tumor cells; 7. liver, lung and Bone metastasis: tumor invades blood vessels and distant metastasis occurs, and up to 15% of patients have metastasis in distant septal sites, which is the main cause of death of MTC patients. First-aid measures MTC is a slowly progressive disease, and first-aid should be sought immediately only when the following conditions occur: 1. Large-scale local growth of the neck mass, compression of the nearby trachea and esophagus; 2. Delayed treatment, there has been significant chest tightness, shortness of breath and difficulty in swallowing. First-aid measures are as follows: 1. adopt a semi-recumbent position; 2. reduce active and passive activities; 3. give oxygen when available; 4. go to a regular hospital for appropriate tracheotomy. Depending on the size of your thyroid nodule, your age at the time of diagnosis, and the presence of cervical lymph node metastases and distant spread, your physician will choose one or several combination treatments that are appropriate for you: (1) surgery is currently the treatment of choice for MTC; (2) other treatments include radiotherapy, chemotherapy, and drug interventions; (3) radiotherapy and chemotherapy are currently considered palliative treatments only when they are ineffective in controlling the disease; (4) the new molecular targeting therapy is the most effective way to treat MTC; (5) the new molecular targeting therapy is the most effective way to treat MTC. 4. new molecularly targeted therapeutic agents for adult patients with advanced (metastatic) MTC; 5. recent developments in radioimmunotherapy and vaccination therapy.