1. What is a thyroid nodule?
A lump in the thyroid gland is collectively called a thyroid nodule and is the most common type of thyroid disorder. Nodules are found by palpation in about 3-7% of cases, while ultrasonography can reveal nodules in 20-76% of subjects. They are more common in women than in men (4:1) and more common in middle-aged and older people than in adolescents, so thyroid nodules are found quite often in women after middle age by ultrasonography. In fact, a nodule is just a morphological description of a thyroid swelling caused by a tumor, cyst, inflammatory mass or other disease. Some benign nodules grow faster and resemble malignant tumors, while some malignant tumors grow slowly and resemble benign nodules. Therefore, the nature of thyroid nodules cannot be determined by physical examination or ultrasonography alone, but also by medical history, physical examination, laboratory tests, and even pathological examination. Of course, objectively speaking, the vast majority of thyroid nodules are benign, with malignancy accounting for only 5%. And even malignant thyroid nodules are much less aggressive than lung cancer. Therefore, once a nodule is found, there is no need to panic and never to be rash.
2.Why do thyroid nodules grow?
The etiology of thyroid nodules is complex and is currently believed to be related to radiation exposure, autoimmunity, genetics, iodine intake and other factors. History of radiation exposure is an important causative factor for thyroid cancer. Individuals who received radiation doses of 10-1000 rad during childhood have a higher incidence of thyroid cancer. Patients with autoimmune thyroiditis are prone to develop thyroid nodules. There is no evidence that other thyroid cancers are hereditary except for familial medullary carcinoma, and only about 7% of patients with papillary thyroid cancer may have a familial predisposition. Severe iodine deficiency can cause endemic goiter, but excessive iodine intake can also cause a variety of thyroid disorders, such as abnormal thyroid function and thyroid nodules.
3. Can thyroid nodules affect my health?
Whether a thyroid nodule affects health depends on the pathological nature, size, growth pattern and function of the nodule. The pathological nature, in short, is often referred to as benign or malignant, but of course this is a broad classification, and there are many subcategories within each broad category; in general, malignant nodules can be dangerous to our health, while benign nodules can cause some discomfort at best. Inflammatory nodules, such as subacute thyroiditis, may cause fever and neck pain; if the nodule is too large or invasive, it may compress the esophagus, trachea, and nerves, resulting in difficulty swallowing, choking, difficulty breathing, and hoarseness; if the nodule is able to secrete thyroid hormones on its own, it may cause symptoms of hyperthyroidism, such as panic, fever, excessive sweating, hunger, and weight loss; if If hypothyroidism is associated with the nodule, the symptoms may include chills, swelling, memory loss, etc. If the nodule is necrotic and bleeding, the neck lump may suddenly increase in size and cause pain. Of course, the majority of benign nodules do not cause any subjective discomfort and can live with you peacefully.
4.How can I detect a thyroid nodule?
Palpation of the neck during a physical examination is the main method of detecting thyroid nodules, and it is also the easiest and most convenient method. However, the physical examination has limitations because palpation can only detect large or superficial nodules, and the experience of the examiner can have an impact on the detection rate of nodules. Ultrasound not only provides important information about the size, texture, borders, calcification and blood flow signals of nodules, but it is also non-invasive, quick and inexpensive. CT and MRI are not superior to ultrasound in the diagnosis of thyroid nodules and are therefore not routinely used, but only when the nodule is located behind the sternum and cannot be detected by transcervical ultrasound, or when the relationship between the nodule and the surrounding tissue needs to be understood. Because the thyroid gland contains iodine and has a natural contrast advantage with the surrounding tissues, clear images can usually be obtained with CT plain scan; because iodine-containing contrast agents may affect thyroid function, enhanced scans should be avoided in patients with nodules combined with abnormal thyroid function and used only when necessary.
5. What should I do after finding a thyroid nodule?
After finding a thyroid nodule, you should visit an endocrinologist. A detailed history will help to determine the nature of the nodule. Nodules with symptoms of hyperthyroidism may be high-functioning adenomas, or early stages of subacute thyroiditis or Hashimoto’s thyroiditis; nodules with hypothyroidism are usually late stages of subacute thyroiditis or Hashimoto’s thyroiditis, or mucocele; nodules with a history of childhood radiation therapy to the neck, or nodules in children from non-thyroid endemic areas have a higher chance of malignancy; nodules with a family history of thyroid cancer have a higher rate of malignancy; nodules that have been present for years A nodule that has been present for many years should be considered malignant if it increases painlessly and significantly in a short period of time. After nodules are found, some necessary biochemical tests should be done, including thyroid function, autoantibodies and tumor markers. Most patients with nodules have normal thyroid function, and those with TSH abnormalities are less likely to have malignant nodules. Thyroid-specific antibodies TRAb, TPOAb, and TGAb are meaningful for the diagnosis of thyroiditis and have no special significance for the differentiation of benign and malignant. Calcitonin and carcinoembryonic antigen are elevated in medullary thyroid carcinoma. High-resolution ultrasonography is highly sensitive in detecting thyroid nodules, but the specificity for determining benign and malignant is not high.
6.In which cases should fine needle aspiration cytology be performed?
The best way to distinguish benign or malignant thyroid nodules is ultrasound-guided fine-needle aspiration cytology (FNA), for reasons of economy and efficiency. However, so many patients with thyroid nodules cannot all be examined by FNA. FNA is performed mainly on nodules ≥1 cm in diameter and on nodules that are not very large but have
① have had previous radiation therapy to the head and neck.
② Family history of medullary thyroid carcinoma or multiple endocrine neoplasia type II.
③ Age <20 years or >70 years.
④male.
⑤ fast-growing nodules.
(6) hard nodules with indistinct margins.
(vii) Fixed nodules.
(viii) enlargement of cervical lymph nodes.
(9) Hoarseness, cough, difficulty in swallowing, difficulty in breathing, etc.
7. “Cold nodules” is not synonymous with thyroid cancer
Most of the thyroid malignant tumors have a reduced uptake of 131 iodine and the result of isotope scan (ECT) is “cold nodules”. However, the term “cold nodules” is not synonymous with malignancy; “cold” simply means that iodine uptake is significantly reduced. There are many reasons for the reduced iodine uptake of nodules, such as thyroid cysts, where the cystic nodules are filled with cystic fluid and there are very few glandular epithelial cells, so ECT will naturally appear as “cold nodules”. In addition, the preparation before ECT can also affect the test results. If you have eaten seafood (such as kelp, jellyfish, nori, moss strips, etc.), used iodine, or taken medications such as eugenol or thyroid tablets within two months before the test, or eaten sea crabs or shellfish within two weeks, or sea fish, shrimp, or sea snails within a week, the absorption of isotope iodine will be affected, resulting in a “cold nodule” result. The result is “cold nodules”. According to statistics, only about 8% of all “cold nodules” are pathologically confirmed as malignant tumors, and more than 90% of “cold nodules” are benign, so there is no need to see “cold nodules”. Therefore, there is no need to be alarmed by “cold nodules”.
Isotope scan can also observe the location of retrosternal goiter and ectopic thyroid gland, track the metastases of thyroid cancer, determine the recurrence of thyroid cancer, and identify whether the neck lump originates from the thyroid gland or its relationship with the thyroid gland, which is useful for the diagnosis of thyroid nodules.
8.Will fine needle aspiration of thyroid nodules lead to tumor spread?
No. Needle puncture of thyroid nodules is performed with a very fine needle, and the thyroid tissue is aspirated for cytological examination. It is the gold standard for preoperative differentiation of benign and malignant thyroid nodules and is also an effective method for the diagnosis and differential diagnosis of many thyroid diseases. Fine needle aspiration is used to extract the material, and the aspirated tissue is hidden in the needle core due to negative suction, so that it will not leak out and contaminate other levels of tissue, and there is no risk of tumor spread. Therefore, there is no need to worry about the spread of tumor caused by puncture.
9. What are the treatments for benign thyroid nodules?
Not all thyroid nodules require treatment. The tests mentioned above can help doctors distinguish which nodules need treatment and which do not require interventional treatment and can only be followed up and observed. There are several treatment options: medication, surgery, isotopes, and anhydrous alcohol injections. Of course, the treatment plan is chosen on a case-by-case basis and is sometimes adjusted, for example, patients who are initially followed only periodically may need surgery because of rapid nodule growth or calcification. The final treatment plan is developed after weighing the pros and cons and after thorough communication with the patient.
10. What about hyperthyroidism or hypothyroidism with nodules?
It is not uncommon for thyroid nodules to be accompanied by abnormal thyroid function. Some are a direct result of the nodule, as if it were a mother-child relationship: for example, high-functioning adenoma, late stage of nodular goiter; but more often it is just a concomitant state, as if it were a sister relationship: for example, hypothyroidism due to Hashimoto’s thyroiditis, or Graves’ hyperthyroidism with a nodule. In the case of a mother-child relationship, if the nodules are removed, the functional abnormalities are naturally corrected. In the case of high-functioning adenomas, both surgery and isotope therapy can provide a one-two punch of treatment. If the relationship is sister, then separate treatment is needed. Patients with Hashimoto-induced hypothyroidism need to use thyroid hormone to correct the hypothyroidism, while patients with hyperthyroidism should first control the hyperthyroidism with anti-thyroid medication, and then perform surgery if the nodule requires surgery after the hyperthyroidism is controlled.
11. Which nodules are suitable for thyroxine suppression therapy?
In short, nodules in between surgery and follow-up are suitable for thyroxine suppression therapy. Experience has shown that thyroxine has no suppressive effect on larger nodules, so thyroxine suppressive therapy should be selected for nodules that are not large and less than 2 cm in diameter. For nodules that are originally small but are observed to increase in size during follow-up, thyroxine suppression therapy can be used, not only as a treatment tool but also as an indirect way to determine the nature of the nodule by observing the response of the nodule after treatment. If the nodule continues to grow during suppressive therapy, it can be used as an indirect basis for the possibility of malignancy, because it is difficult to perform direct tests such as fine needle aspiration on smaller nodules, and the indirect basis becomes more important at this time.
12. Which patients are not suitable for thyroxine suppression therapy?
Suppressive therapy for thyroid nodules requires patients to take more than physiologically necessary doses of thyroxine to cause artificial hyperthyroidism, thereby suppressing the pituitary gland’s secretion of thyrotropin (TSH), a key hormone that may lead to goiter and tumor growth. Because supraphysiologic doses of thyroid hormone can cause increased heart rate, increased myocardial oxygen consumption, and loss of bone calcium, they are not indicated for patients with pre-existing tachycardia, tachyarrhythmia, coronary artery disease, hypertension, severe diabetes, osteoporosis, insomnia, and menopausal women and elderly patients, as their pre-existing symptoms are exacerbated to varying degrees after taking the drug. patients with already low TSH levels are not indicated because these TSH in patients is often not the cause of the thyroid nodule and therefore suppressive therapy is not necessary. Thyroid nodules caused by pituitary TSH tumors have high TSH, but thyroxine suppression therapy is ineffective and can aggravate hyperthyroidism, and should be treated with pituitary tumor resection or Gamma Knife.
13. Which nodules need surgery?
A case-by-case analysis is needed. The following cases are recommended for surgical treatment.
(1) For those with rapid growth, high suspicion of malignancy, and confirmed malignancy by puncture.
(2) Those with large nodules, symptoms of pressure, and poor results of non-surgical treatment.
(3) Nodules with combined hyperthyroidism.
14.What do patients with thyroid nodules need to pay attention to in terms of diet?
A specific analysis is needed. First of all, we need to clarify the causes and classification of thyroid nodules, and adopt the appropriate diet according to the different conditions of thyroid nodules. In the case of Graves’ hyperthyroidism with thyroid nodules, a strict iodine avoidance diet, iodine-free salt and seafood such as kelp, seaweed and sea fish are prohibited; in the case of Hashimoto’s thyroiditis with nodules, iodine avoidance is not necessary, but a large amount of food with high iodine content will increase damage to thyroid follicular cells and antibody production, aggravating the destruction of thyroid cells. If the nodule is a high-functioning adenoma that can secrete thyroid hormone, iodine should be strictly avoided because iodine is one of the raw materials for thyroid hormone synthesis, and iodine intake will also increase the synthesis of thyroid hormone and worsen the symptoms of hyperthyroidism. If it is a non-functioning nodule, which means it has no effect on thyroid function, there is no need to avoid iodine in the diet. It is recommended to consume less food such as radish and cabbage, as current studies have found that these two foods can promote the growth of thyroid nodules.
15.What are the types of thyroid cancer?
Papillary carcinoma, follicular carcinoma, undifferentiated carcinoma, medullary carcinoma, squamous carcinoma and lymphoma.
16.What are the treatment methods for thyroid cancer?
The main treatment methods are surgery, endocrine therapy, radiation therapy and chemotherapy. Once thyroid cancer is diagnosed, surgery is the first treatment. After surgery, endocrine therapy is required, i.e. thyroid hormone suppression and replacement therapy, and thyroid function and thyroglobulin follow-up to prevent recurrence of thyroid cancer. For thyroid cancer with metastasis, radioactive 131 iodine ablation therapy can be used after surgery to eliminate residual thyroid tumor cells and prevent metastasis or recurrence of the tumor. Internal medicine for thyroid tumor treatment is not commonly used in China at present.
17.Can thyroid tumors be hereditary?
At present, there is only one type of thyroid tumor with clear hereditary tendency, namely medullary thyroid carcinoma, which is a malignant tumor derived from calcitonin-secreting C cells and has a high degree of malignancy. Patients may have medullary thyroid carcinoma alone or both parathyroid adenoma and adrenal pheochromocytoma, and may have clinical manifestations of hyperparathyroidism or hypertension, the latter being called polyendocrine adenomatosis type 2. The causative gene is the RET proto-oncogene, and genetic diagnosis is now feasible, and risk stratification can be performed according to genotype to determine different treatment strategies.