Location of the thyroid gland.
Below the anterior laryngeal node of the neck, on either side of the trachea, up to the base of the tongue and down to the posterior aspect of the sternum. It consists of two lateral lobes, the left and right, and a narrow isthmus in the middle.
The thyroid gland is not easily palpable in the neck under normal conditions.
Role of the thyroid gland.
The main function is to synthesize and secrete thyroxine. Thyroid hormone mainly promotes the body’s metabolism and affects the growth and development of infants and children. Zhang Yan, Department of Thyroid Neck Tumor, Tianjin Cancer Hospital
Pathogenesis of thyroid tumors.
Benign goiter includes thyroid adenoma, nodular goiter, and thyroiditis (acute, subacute and Hashimoto’s thyroiditis).
Malignant enlargement of the thyroid gland includes thyroid cancer, malignant lymphoma, sarcoma, etc.
Thyroid tumors are quite common, benign tumors account for most of them, about 80-90%, and are more common in women, with a male to female ratio of 1:3. The age of onset is mostly during the period of active thyroid function, mostly at the age of 20-50, and the onset gradually decreases later. Thyroid cancer is a more common malignant tumor, accounting for the first place of head and neck tumors in our hospital, and is also more frequent in women. There are two peak ages of incidence, namely, 7-10 years old and 40-65 years old.
In terms of geographical distribution, coastal areas like our city are the high incidence areas of thyroid cancer, and the incidence rate is significantly higher than inland areas, and the incidence has been on the rise in recent years.
High incidence factors of thyroid cancer.
1.Ionizing radiation: Radiation cancer mostly occurs after X-ray external irradiation. For example, the incidence of thyroid tumor among the survivors of the atomic bombing in Japan has increased significantly. It is important to note that the risk of thyroid cancer decreases with the age of radiation exposure, i.e., the risk is higher in young children than in adults. The younger the irradiated pediatrician is, the higher the risk of developing cancer.
2. Iodine: Thyroid cancer is more common in iodine-deficient areas and also in coastal areas with high iodine levels. In iodine-deficient areas, follicular carcinoma or some interstitial carcinomas of the thyroid gland occur, while in high-iodine areas, papillary carcinomas are more common.
3. Gender and hormones: women are significantly more common than men. Estrogen may be one of the cancer-causing factors.
4.Family factors: Especially medullary thyroid carcinoma, it is often seen that several members of a family have the disease.
Common symptoms of thyroid tumor.
1.Single or multiple nodules in front of the neck, round or oval, cystic or solid, with smooth surface.
2. Most of them are found accidentally, and generally grow slowly. Sometimes the tumor suddenly increases in size and is accompanied by swelling and pain, which is mostly due to bleeding inside the tumor capsule.
3.When the tumor is large, it may have the feeling of compression or compression of trachea displacement, resulting in poor breathing or difficulty in breathing.
4.Thyroid tumor of many years may appear sudden and obvious increase of tumor with or without hoarseness and other symptoms, which may be the sign of tumor malignancy.
Physical examination: The examination of thyroid tumor reveals a swelling in the anterior part of the neck, which moves up and down with swallowing.
Clinical characteristics of thyroid cancer.
1. A thyroid swelling, especially a multi-year swelling with rapid short-term growth may turn from benign to malignant.
2. goiter accompanied by hoarseness and dyspnea.
3. goiter with enlarged lymph nodes in the neck.
4. goiter with swallowing and breathing difficulties.
5. The examination reveals that the goiter has a hard texture, poorly defined borders, uneven surface, adhesions to the trachea and restricted movement.
6. A goiter with prolonged diarrhea and watery stools several times a day may be medullary thyroid cancer.
7.Family history of cancer, especially those with medullary thyroid cancer in the family, and other family members found to have thyroid tumor.
8.Children with thyroid tumor may have high possibility of malignancy, especially those who have received radiation in front of the neck.
However, the above symptoms do not confirm the diagnosis of thyroid cancer, so you should seek medical consultation in time after finding a thyroid swelling to avoid delaying the diagnosis.
Several misconceptions
1. Is thyroid cancer a big neck disease?
No, it is not. Great neck disease is a benign enlargement of the thyroid gland, which forms a lump in front of the neck or on both sides of the trachea and grows gradually, and is medically known as nodular goiter. Most of them occur in mountainous areas, where endemic goiter is endemic. However, in a few patients, the sudden growth of the swelling accelerates, which is a sign of malignant change, that is, it may turn from benign to malignant cancer, so you need to ask your doctor for a timely examination.
2. Is it more dangerous to have more thyroid tumors?
No, it is not. Multiple thyroid nodules, often called nodular goiter, are benign lesions, and very few have cancer. A single nodule in the thyroid is usually a benign adenoma, but about 10-20% may be cancerous, which is difficult to distinguish clinically. Especially for small nodules less than 2 cm in diameter, the patient has no discomfort and it is difficult for the doctor to feel them by hand. Therefore, single nodule of thyroid should be taken seriously and treated actively.
3.Does painful thyroid tumor mean cancer?
Not necessarily. Most of the thyroid tumors and thyroid cancer are painless. However, cystic thyroid adenoma
This is due to bleeding inside the tumor capsule or infection. After the blood is gradually absorbed, the tumor may shrink to different degrees and the pain will be reduced or disappeared; acute and subacute thyroiditis will be accompanied by pain when the thyroid gland is enlarged; advanced thyroid cancer will have pain.
4.A tumor with long growth time is benign tumor?
Not necessarily. Most of the thyroid cancers are low grade malignant and grow slowly, with an average disease duration (the time between the discovery of the lump and the consultation) of 5-6 years. The longest can be up to 30 years. This is the difference between thyroid cancer (in terms of papillary and follicular thyroid cancer) and other cancers. Therefore it is difficult to say that a thyroid lump that has been present for more than 10 years is not cancerous.
5.What are the manifestations of tumors that have existed for many years that should be considered cancer?
A. Rapid growth, hardening and poor activity within a short period of time.
B.Sudden onset of hoarseness and difficulty in breathing.
C.Sudden appearance of difficulty in swallowing.
D. The appearance of enlarged lymph nodes in the neck.
6.Are most thyroid tumors in children benign?
Not necessarily. The malignancy rate of thyroid cancer in children, especially single tumor, is significantly higher than that of adults, up to 50%.
7.Does the younger the patient with thyroid cancer, the worse the prognosis?
No. The younger the thyroid cancer patient, the worse the prognosis? Younger thyroid cancer patients are prone to lymph node metastasis in the neck, but the prognosis is good and most of them can be cured after regular surgical treatment; while older patients have a low incidence of lymph node metastasis in the neck, but there is a high possibility of local invasion of surrounding tissues (trachea, esophagus, blood vessels, etc.), which is not easy to be completely removed by surgery, so the prognosis is worse than younger patients.
8.Is it better to give up the treatment if distant metastasis (lung, liver, etc.) is found in thyroid cancer?
No, it is not. Because most of thyroid cancers are less malignant and can survive for many years with tumor after distant metastasis occurs, while local tumor of thyroid gland, if left untreated, will often compress the surrounding tissues such as trachea and esophagus and affect the survival, therefore, even if distant metastasis is found, the larger local tumor should still be actively removed to prolong life.
Typing of thyroid cancer.
There are four main types of thyroid cancer, with different malignant degree and prognosis.
Papillary carcinoma: It accounts for the majority of thyroid carcinoma, with low malignancy and easy to metastasize to lymph nodes, and after thorough surgical treatment, satisfactory results can be obtained.
Follicular carcinoma: The prognosis is slightly worse than that of papillary carcinoma, and it is prone to blood metastasis. However, with timely treatment and thorough surgery, the effect is still quite satisfactory.
3.Medullary carcinoma: Although it is not as good as the first two types, it has better efficacy than the fourth type, and most patients can survive for a long time after timely surgery.
4.Undifferentiated carcinoma: It is the most malignant among thyroid cancer and develops very fast. Most of the patients are in advanced stage when they are diagnosed, and the treatment effect is very poor. Fortunately, there are only a few patients in this category.
In conclusion, most thyroid cancers have a good prognosis and are not incurable, it should be said that “having cancer is unfortunate, but having thyroid cancer is the most fortunate of all”.
The examination means of thyroid cancer are
1.B ultrasound: non-invasive examination, which can clarify the size, shape and boundary of the tumor, and determine the benignity and malignancy and whether there is metastasis. B ultrasound in our hospital has a diagnosis rate of benign and malignant thyroid tumors of more than 90%, which is an important routine examination means.
2.CT and MR: It can clarify the scope of lesion, determine the expansion of tumor into the thoracic cavity and the relationship with surrounding blood vessels, and provide a reliable basis for the formulation of treatment plan.
3.PET/CT: It can identify the benignity and malignancy of the primary foci and the presence of regional lymph nodes and distant metastases to improve the staging, and evaluate the postoperative efficacy.
4.Tumor markers: Calcitonin (CT) is a specific tumor marker for medullary thyroid carcinoma. CT value of medullary carcinoma patients is often elevated, which can help to make a clear diagnosis and determine postoperative recurrence and metastasis.
5.Biopsy: For resectable thyroid tumors, preoperative biopsy is usually not performed and surgical resection is performed. If malignancy is suspected, intraoperative frozen section examination will be performed to clarify the benign and malignant nature to determine the scope of surgery. For huge tumors that cannot be completely removed in late stage, needle aspiration biopsy is feasible to clarify the diagnosis and determine the treatment mode.
Treatment.
Thyroid tumors are generally treated by surgery, especially when there are local pressure symptoms, malignant possibility and huge tumors should be actively operated. Drug treatment for multiple or small nodules can sometimes shrink or disappear the tumor. Cancer hospitals have their own formulated Thyroid III, which has good effect on the treatment of benign thyroid tumor.
Surgery is the first choice and the most effective treatment for thyroid cancer. Standardized surgery is the key to cure thyroid cancer.
Surgical treatment of primary cancer
If both glands are involved, unless both glands have been invaded by the tumor, the upper or lower part of the thyroid gland should be preserved. In this way, while completely removing the tumor, the function of the thyroid gland and parathyroid gland is preserved to the maximum extent, which reduces the occurrence of complications and improves the quality of life of patients.
Surgical treatment of cervical lymph node metastasis
The most common metastatic route of thyroid cancer is cervical lymph node metastasis. If cervical lymph node metastasis has already appeared clinically and the primary cancer can be resected, combined radical thyroidectomy is recommended. For patients who have not yet developed cervical lymph node metastasis, zoned cervical lymph node dissection is performed according to the patient’s gender, age, tumor envelope invasion and tumor histological variant.
Functional cervical lymph node dissection is based on the traditional radical dissection to maximize the physiological function of the patient and completely remove the tumor. At present, multi-functional cervical lymph node dissection has become a routine procedure in our hospital, which has greatly improved the survival quality of patients.
Endocrine therapy
Thyroxine can inhibit the secretion of thyrotropic hormone in the anterior pituitary gland, thus inhibiting the proliferation of thyroid tissue and the growth of cancerous tissue. Therefore, patients take oral thyroxine after surgery, which is useful for preventing recurrence and treating advanced thyroid cancer.
Because thyroid cancer is more common in women, for patients with advanced stage and distant metastasis, ER and PR tests for tumor are feasible, and those who are positive can take endocrine therapy such as triamcinolone after surgery to control the development of the disease.
Other treatments
Thyroid cancer is less sensitive to radiotherapy and chemotherapy, but for inoperable or distant metastatic advanced cancer, especially undifferentiated cancer, chemotherapy and radiotherapy are still one of the means to control the progression of the disease.
Although most of thyroid cancers are long-lived and slow-growing, they are still fatal diseases and should be treated actively and correctly to get a higher chance of cure.
Prevention of thyroid cancer
1. Avoid exposure to radiation exposure and known carcinogens.
2. timely treatment of thyroid nodules.
3. Pay attention to the consumption of seafood such as seaweed and nori in daily diet, but residents of our city should not intentionally supplement iodine.
4.Pay attention to controlling bad emotions in daily life.
5.People with family history should pay attention to regular examination.