What are the clinical manifestations of thyroid tumor? 1. Thyroid adenoma: Most of the patients have no symptoms, mostly found by chance, generally with long course and slow development. Early manifestation is painless lump in anterior neck area, mostly single, round, oval or nodular, varying in size, clear border, medium hardness, smooth surface, good mobility, and can move up and down with swallowing. Because of no discomfort, it is mostly date like in size when found. Sometimes, the tumor can suddenly increase in size and be accompanied by distension and discomfort, mostly due to bleeding within the tumor capsule. Very few larger adenomas may have tracheal compression, but compression of the recurrent laryngeal nerve is extremely rare. 2.Papillary thyroid carcinoma: it is common in young women, with low malignancy, slow growth, no discomfort, late diagnosis, average disease duration about 5 years, individual can reach 30 years, so it is mostly misdiagnosed as benign tumor. The tumor is mostly solitary, hard, irregular, with unclear border and poor mobility. Larger tumors are often associated with cystic changes, and light brownish-yellow liquid can be extracted by puncture, which is easily misdiagnosed as cyst; smaller ones are not easily palpable, and are often diagnosed by finding metastatic enlarged lymph nodes. In advanced stage, the tumor may invade and compress the adjacent tissues and organs, causing hoarseness, difficulty in breathing and dysphagia. This type of lymph node metastasis can occur at an early stage, more than half of the patients have metastasis at the time of initial diagnosis, while hematogenous metastasis is less common, accounting for only 4-8.6%. Follicular carcinoma of thyroid gland: It is often found in middle-aged people, mostly in iodine-deficiency goiter endemic areas, and some patients have a history of nodular goiter for many years. Generally, the course of the disease is long and the growth is slow, but a few patients may have a recent increase in growth. The masses are mostly solitary, solid, hard, mobile, smooth, with indistinct borders, and often lack any indication of local malignancy. Hematogenous metastasis is common, and lymphatic metastasis occurs less frequently, and some patients can be seen with bone metastasis as the first symptom. The metastatic cancer tissue can be well differentiated and resembles the normal thyroid follicular structure and has strong iodine uptake function, so it is called “benign metastatic thyroid adenoma”. Medullary thyroid carcinoma: This type is rare, and the mass is mostly confined to one lobe of the gland, with slow growth and long course. Medullary carcinoma originates from parafollicular cells of the thyroid gland, which do not have the function of synthesizing and secreting thyroxine, but mainly secrete calcitonin, prostaglandin, 5-hydroxytryptamine and other biologically active substances, so the clinical manifestations of medullary carcinoma are very different from other types of thyroid cancer. About 30% of patients with medullary carcinoma have persistent diarrhea, which is watery and dilute, about 10 times a day, accompanied by flushing. After resection of the tumor, the diarrhea disappears, but when the metastasis recurs, the diarrhea recurs again. There are 10%-20% of patients with medullary carcinoma have family tendency and are accompanied by various endocrine diseases, such as pheochromocytoma, carcinoid syndrome, Cushing’s syndrome, etc., which are now confirmed to be orthosomal inheritance. Lymphatic metastasis is the main cause of medullary carcinoma, and about 60% of patients have lymph node metastasis in the neck at the time of initial diagnosis. 5.Undifferentiated thyroid carcinoma: It is a type of highly malignant tumor, including large cell carcinoma, small cell carcinoma, spindle cell carcinoma, squamous cell carcinoma, mucinous adenocarcinoma, etc. It is common in elderly men. Patients with undifferentiated carcinoma usually have a history of goiter or thyroid nodules for many years. The masses suddenly increase in size recently, develop rapidly and invade adjacent tissues within a short period of time, resulting in hoarseness, choking, pain, dyspnea, dysphagia, and diffuse bilateral giant thyroid masses that are hard, fixed and not smooth when examined. The rate of metastasis to the lymph nodes in the neck is high and often prone to hematogenous metastasis.