Undifferentiated carcinoma of thyroid gland occurs mostly at the age of 60, mainly manifested by rapid enlargement of thyroid lumps, pain, atypical cells and multinucleated giant cells, and the treatment methods include surgery and chemotherapy. 1. Prevalent age: mostly around 60 years old, preferred in females. Undifferentiated carcinoma accounts for 5%~10% of thyroid cancer, and distant metastasis in lung, bone and brain can occur at early stage. The average survival time is relatively short. 2. Clinical manifestations: mainly rapid enlargement and pain of thyroid lumps. When the tumor infringes on the surrounding tissues, it can lead to dysphagia, respiratory distress and hoarseness. The mass is hard and adheres to the surrounding tissues, and there may be pressure pain, enlargement of local lymph nodes, and distant metastasis may also occur. 3. Pathology: high degree of malignancy, the main microscopic manifestation is multinucleated giant cells and atypical cells with many nuclear divisions. 4. Treatment: including surgical treatment, radiotherapy, chemotherapy, thyroid hormone inhibition therapy, I¹³¹ treatment, etc. Patients with undifferentiated carcinoma of thyroid should go to the hospital in time and receive standardized treatment under the guidance of doctors.