Thyroid cancer

Overview of thyroid cancer accounts for all cancer 1% in local nodular goiter prevalence, Thyroid cancer is particularly poorly differentiated thyroid cancer incidence rates are high. Age incidence rate among men below the 3 year / 100,000, while women do two-high three times. various types of thyroid cancer are also differences in age distribution, papillary adenocarcinoma most widely distributed, can occur in children under the age of 10 to centenarians, follicular cancer was particularly prevalent in the 20-100-year-old, Medullary cancer was particularly prevalent in the 40-80-year-old, undifferentiated carcinoma was particularly prevalent in the 40-90-year-old. The exact etiology of specific causes of the current uncertainty about, but from an epidemiological survey, and experimental tumor research and clinical observation, the incidence of thyroid cancer may be related to the following factors. (1) radiation injury with X-ray irradiation did the thyroid can induce animals thyroid cancer. Experimental I can prove 131 thyroid cell metabolism changes, nuclear deformation, the synthetic thyroxine greatly reduced. While radiation can be seen arising from the abnormal thyroid cell division, resulting in cancer; the other thyroid damage could not have endocrine factors, As a result, the thyroid stimulating hormone (TSH) secretion can trigger thyroid cancer cells. Clinically, many facts show the incidence of thyroid with radiation effects. Of particular note is that Baby-in period had enlarged thymus or lymph nodes - proliferation and to accept the mediastinum or neck radiation therapy of children particularly vulnerable to the thyroid cancer, it is because children and adolescents in the proliferation of cells, radiotherapy is an additional stimulus, easily trigger tumor formation. Adults in the neck after radiation therapy of thyroid cancer is rare opportunity. (2) of iodine and iodine TSH perturbations or excessive thyroid iodine deficiency can cause the structure and function of change. Switzerland endemic goiter prevalence of thyroid cancer incidence rate of 2% over Berlin and other non-pop 20 times higher. In contrast, iodine diet would also easily induced thyroid cancer, Iceland and Japan are the highest in the perturbation iodometric countries, thyroid cancer detection rate than other countries. This may stimulate the TSH and thyroid hyperplasia factors. Experiment shows that the long-term TSH stimulation can induce thyroid hyperplasia, forming nodules and cancer. (3) Other clinical thyroid disease with thyroid cancer, chronic thyroiditis. nodular goiter or carcinogenic toxic goiter reports But these thyroid disease and thyroid cancer certainly difficult relationship. To thyroid adenoma example, the great majority of thyroid follicular adenoma type, only 2 - 5% of the papilloma; If thyroid cancer from adenomatous change from, for the vast majority of follicular type, In fact more than half of thyroid cancer served as the first-cancer, thyroid adenoma speculate the incidence of cancer is very small. (4) genetic factors about 5 ~ 10% of medullary thyroid cancer of family history often associated with pheochromocytoma, etc. Run, suggesting the occurrence of this cancer may be related to chromosome genetic factors. Pathological changes (1) of papillary adenocarcinoma of thyroid cancer is the most common type, accounting for about 70%. Sizes. General well-differentiated, low degree of malignancy. Cancer crispy soft and fragile and color dishes; But elderly patients Zhuang papillary carcinoma of the more rigid and pale. Papillary cancer center often cystic degeneration, capsule filled with bloody fluid. Sometimes cancer tissue calcification may occur, the cut surface sand samples. These cystic degeneration and calcification and the malignant tumor and prognosis. Seen under the microscope by columnar epithelial carcinoma papillae composition, sometimes mixed with follicle-like structure, even found papillary follicular to the kind of variation. Papillary adenocarcinoma leaves a complete envelope of late can also break the capsule and invasion of surrounding tissues, Sowing is mainly used lymphatic Most cervical lymph node metastases were the most common, About 80% of children and 2% of adult patients will palpable lymph nodes, followed by the transfer of blood to the lung or bone. (2) follicular adenocarcinoma than papillary adenocarcinoma rare thyroid cancer accounts for about 20%, ranking the second place, their average age of patients with papillary carcinoma than those large. Cancer is soft, flexible, rubber-like, circular, oval or sub-leaf-shaped nodules. Cut surface reddish-brown, showing fibrosis and calcification, hemorrhage and necrosis lesions. Well-differentiated adenocarcinoma in follicular microscope with normal thyroid similar to the organizational structure, but coated, vascular and lymphatic invasion by the phenomenon; poorly differentiated adenocarcinoma were follicular see irregular structure, Incorporation into cell-intensive or strip-shaped, rarely formed follicles. Although the disseminated by means of lymph node metastasis, but mainly through the transfer of blood to the lung, bone and liver. Some follicular adenocarcinoma in patients after resection separated for a long time before relapse see, but the prognosis not good papillary adenocarcinoma. (3) medullary thyroid carcinoma of the thyroid cancer accounts for 2 ~ 5%. Hazard from the disease in 1959 first described, Calcitonin is the secretion of thyroid associated with pheochromocytoma and thyroid gland hyperplasia (II-type multiple endocrine tumor, MEN II) characteristics. Medullary thyroid cancer from embryos after body in the gills (ultimobranchial body). from the bright side of follicular cells (C cells) from changes. Follicular cells are derived from adjacent neural crest cells of the endocrine, these endocrine cells with a common function, It is able to uptake 5 - serotonin and dopamine precursors, and with the decarboxylase be decarboxylation, Therefore, also known as amine precursor uptake decarboxylation cells (amine precursor uptake and de carboxylation), or APUD cell. Single tumor nodules, sometimes multiple, quality hardware and fixed, amyloid deposition, little uptake of radioactive iodine. Cell morphology mainly by the polygon and spindle cell components, with diversification. (4) undifferentiated thyroid carcinoma of the thyroid cancer accounts for 5%, occurring mainly in middle-aged and older patients, male preponderance. Mass transfer rules without hard, fixed, fast-growing quickly diffuse involving the thyroid gland, usually in a short period of time could be infiltrating the trachea, muscle, nerves and blood vessels and cause difficulty in breathing and swallowing. Local tumor may have tenderness. See under the microscope by the major cancer organizations poorly differentiated epithelial cells, the cells were polymorphic, it is common to mitosis. Cervical lymphadenopathy may arise, but also of lung metastases. The prognosis of the disease is poor, the radioactive iodine therapy, external irradiation only partial control symptoms.