A thyroid nodule is a mass or masses of abnormal tissue structure in the thyroid gland due to various causes. In Chinese medicine, it is classified as a “gall disease”.
The presentation of thyroid nodules varies with different methods of examination. Palpation: A nodule is a mass that can be felt in the thyroid area. Ultrasound: nodules are focal areas of abnormal echogenicity in the thyroid gland. There is inconsistency in the detection of nodules between the different examination methods: thyroid nodules palpated on examination and not suggested by ultrasound; nodules not palpated on examination but detected by ultrasound; a single nodule palpated on examination but multiple nodules suggested by ultrasound.
The prevalence of thyroid nodules in the general population: palpation 3-7%, ultrasound 20%-70%.
The vast majority of thyroid nodules are benign and only 5% are malignant.
Nodules are classified according to their etiology as
1. hyperplastic nodular goiter.
2, neoplastic nodules: benign tumors, malignant tumors.
3, cysts.
4, inflammatory nodules.
The core of the diagnosis is to identify the benign and malignant nodules. And detailed history taking and comprehensive physical examination are the basis for correct diagnosis.
Clinically, thyroid nodules are mostly detected by physical examination or ultrasonography; most are asymptomatic; very few have local pressure manifestations.
A few have abnormal thyroid function, hyperthyroidism or hypothyroidism manifestations. As an endocrinologist, we should focus on the patient’s age, gender, history of head and neck radiotherapy, nodule size, growth rate, local symptoms, symptoms related to abnormal thyroid function and the patient’s family history; whether there are thyroid tumors, medullary thyroid carcinoma, MEN type 2, familial polyposis, Cowden’s disease and Gardner’s syndrome in the family ‘s syndrome, etc. Attention should also be focused on: number, size, texture, mobility, tenderness, and local lymph node enlargement of the nodule.
Clinical evidence suggesting a malignant thyroid nodule: history of treatment with neck radiography, family history of medullary thyroid carcinoma or MEN2, age less than 20 years or more than 70 years, male, significant short-term enlargement of the nodule, and symptoms of local compression, including persistent hoarseness, dysphonia, dysphagia, and dyspnea. The nodules are hard, irregularly shaped, fixed, and associated with enlarged lymph nodes in the neck.
What other tests should be done when a thyroid nodule is found?
1. Laboratory tests.
①Thyroid function tests. All patients with thyroid nodules should have their serum TSH and thyroid hormone levels measured. The majority of patients with malignant nodules have normal thyroid function. If serum TSH is below normal and nuclear imaging suggests a high-functioning nodule, the nodule is almost always benign.
②Serum TPOAb and TgAb tests. Tests for these two antibodies are clinical diagnostic indicators of Hashimoto’s thyroiditis. However, the diagnosis of Hashimoto’s thyroiditis still does not completely exclude the possibility of malignancy, and a small number of Hashimoto’s thyroiditis may be combined with papillary thyroid cancer or thyroid lymphoma.
(iii) Measurement of thyroglobulin (Tg) levels. A variety of thyroid disorders can lead to elevated serum Tg levels, and the measurement of Tg is not helpful in identifying benign or malignant nodules. However, it can play an important role in suggesting whether there is recurrence of malignant thyroid nodules after surgery.
④The measurement of serum calcitonin level. It has diagnostic significance for medullary carcinoma. Those with family history of medullary thyroid carcinoma or family history of MEN2 should have their serum calcitonin levels measured in the basal or stimulated state.
2.High definition thyroid ultrasonography is the most sensitive test to evaluate thyroid nodules. It can be used not only to identify the nature of the nodule, but also to localize, puncture, treat and follow up on thyroid nodules under ultrasound guidance. This test is required for all patients suspected of having a thyroid nodule or who already have a thyroid nodule. The report should include the location, morphology, size, number of nodules, nodule margins, internal structure, echogenic features, blood flow and cervical lymph nodes.
The features of high-resolution thyroid ultrasonography suggestive of malignant nodules: microcalcifications, irregular nodule margins, and disturbance of blood flow signal within the nodule; these three features suggest a high specificity of >80%, but a low sensitivity of 29%-77,5%. One feature alone is not sufficient to diagnose a malignant lesion. However, if more than 2 features are present at the same time or if one of the features is present in hypoechoic nodules, the sensitivity of the diagnosis of malignant disease can be increased to 87%-93%.
Other features of high-resolution thyroid ultrasonography that suggest malignant nodules include: invasion of the hypoechoic nodules into the outer thyroid envelope or the muscles surrounding the thyroid gland; hypoechoic nodules with enlarged cervical lymph nodes, accompanied by loss of lymph node portal structures, or cystic changes, or microcalcifications in the lymph nodes, or disturbances in the blood flow signal.
3.Thyroxine imaging: It is the only imaging method that can evaluate the functional status of nodules. The nodules can be classified as “hot nodules”, “warm nodules” and “cold nodules” according to their ability to take up radionuclides. The percentage of “hot nodules” is 10% and the percentage of “cold nodules” is 80%. Ninety-nine percent of “hot nodules” are benign, and malignancy is extremely rare; the malignancy rate of “cold nodules” is 5-8%. Therefore, the use of “cold nodules” to determine the benignity and malignancy of thyroid nodules is not very helpful. This method is used in cases of thyroid nodules combined with hyperthyroidism or subclinical hyperthyroidism to determine whether the nodule is a “hot nodule”. It is important to note that in cases of cystic nodules or thyroid cysts, the thyroid nuclei may also appear as “cold nodules”. This should be analyzed together with the ultrasound findings of the thyroid gland.
MRI and CT of the thyroid gland are less sensitive than ultrasound of the thyroid gland in detecting thyroid nodules and determining the nature of the nodules, and are expensive. Therefore, it is not recommended for routine use. However, it has special diagnostic value in assessing the relationship between thyroid nodules and surrounding tissues, especially for the detection of retrosternal goiters.
5. Fine needle aspiration cytology biopsy of the thyroid (FNAC): the most reliable and valuable diagnostic method for identifying benign and malignant nodules. The literature reports 83% sensitivity, 92% specificity and 95% accuracy; FNAC should be performed for suspected malignant changes.
FNAC can be used to clarify the cytological type of the cancer before surgery and help determine the surgical plan. It is worth noting that FNAC cannot distinguish follicular carcinoma from follicular cell adenoma.
Points of note.
The benignity or malignancy of a nodule is independent of the size of the nodule, and malignancy is not uncommon in nodules less than 25 px in diameter.
the benignity or malignancy of a nodule is not related to whether the nodule is palpable or not
the benignity or malignancy of a nodule is not related to whether the nodule is solitary or multiple
The benignity or malignancy of a nodule is not related to whether the nodule is combined with a cystic lesion.
Treatment: Do the nodules require treatment? How to choose the method of treatment? These are the most important and frequently asked questions by patients. So, what is the basis? Here, I would like to tell you that the choice of treatment should depend on the characteristics of the thyroid ultrasound and the results of the FNAC, as well as on the patient’s requirements.
For the management of malignant thyroid nodules: surgery is the first choice for most malignant thyroid tumors. Undifferentiated thyroid cancer is extremely malignant and almost always has distant metastases at the time of diagnosis, so surgery alone is difficult to achieve therapeutic goals, so a combination of treatments should be used. Thyroid lymphoma is sensitive to chemotherapy and radiotherapy, so once diagnosed, chemotherapy or radiotherapy should be used. For the management of benign nodules: The majority of patients with benign thyroid nodules do not require special treatment. Follow-up is required, every 6 months – 12 months. Ultrasound of the thyroid gland is done and FNAC is repeated if necessary. only a few patients require treatment with surgery, drugs and PEI.
Several treatments are available for benign nodules.
①L-T4 suppression therapy.
②Surgical treatment.
③ ultrasound-guided percutaneous alcohol injection (PEI).
④radioactive 131 iodine therapy.
⑤ Chinese medicine.
The purpose of L-T4 suppression therapy: to shrink existing nodules and prevent the production of new nodules. However, the overall effect is not satisfactory. Adverse effects are clear. Not recommended for widespread use, only for a few benign thyroid nodules. Indicated for: patients living in iodine-deficient areas; small nodules and young age; nodules with non-autonomous function; not suitable for: male patients with serum TSH levels <1mU/L and older than 60 years; postmenopausal women; combined cardiovascular disease; combined osteoporosis; combined systemic diseases. If thyroid nodules do not shrink after 3 to 6 months of L-T4 treatment, or if nodules increase in size instead, FNAC needs to be repeated.
Surgical treatment – Indications: Patients with thyroid nodules with local pressure symptoms; with hyperthyroidism; progressive enlargement of nodules; FNAC suggesting suspicious carcinoma.
Ultrasound-guided percutaneous alcohol injection (PEI).
It is a minimally invasive method for the treatment of thyroid nodules. It is mainly used to treat thyroid cysts or nodules combined with cystic changes. This method has a high recurrence rate. Large or multiple cysts may require multiple treatments to achieve better results. This method is not recommended for solid benign nodules. detailed knowledge of the location, size, morphology, margins and blood flow status of the nodule should be obtained before PEI. The position of the puncture needle tip should be monitored at all times during the procedure to ensure that the needle tip is located inside the nodule. Attention should be paid to the patient’s reaction, and once the patient shows signs of severe pain, cough or change in pronunciation, the operation should be stopped immediately and should be performed by an experienced physician.
Radioactive 131 iodine treatment; the aim is to remove functionally autonomous nodules and restore a normal functional state of the thyroid. The effectiveness is up to 80-90%. Indicated for: autonomic high-functioning adenomas; toxic nodular goiter with thyroid volume less than 100 ml; inappropriate for surgical treatment or surgical treatment of recurrent toxic nodular goiter. Not suitable for those with large nodules; contraindicated in pregnant and lactating women !!! What is the management of suspected malignant and undiagnosed thyroid nodules? If the diagnosis of cystic or solid thyroid nodules is not clear by FNAC examination, the FNAC examination should be repeated. If the diagnosis is still not confirmed by repeated FNAC tests, especially if the nodule is large and fixed, surgery is required.
Management of thyroid nodules in children; relatively speaking, thyroid nodules in children are rare, but the malignancy rate is higher than in adults, with cancer accounting for 15%. FNAC should also be performed on pediatric patients with thyroid nodules. When cytological examination suggests that the nodule is malignant or suspicious of malignancy, surgical treatment should be undertaken. Management of thyroid nodules during pregnancy: The management of thyroid nodules found during pregnancy is the same as that of thyroid nodules found during non-pregnancy. Thyroid nucleography and radioactive 131 iodine therapy are prohibited during pregnancy. fnac can be performed during pregnancy or postponed to the postpartum period. Timing of surgery for malignant nodules: It is safer to perform the surgery in the 3rd-6th month of pregnancy. Otherwise, surgery should be performed after the option of postpartum. If surgery is needed when malignancy is not suspected or when there are obvious signs of pressure, it should be scheduled as far as possible in the postpartum period.
TCM etiology and pathogenesis.
Chinese medicine believes that thyroid nodules are related to water and soil causes, emotional and mental disorders, and physical factors. The pathogenic mechanisms are generally: stagnation of qi and blood, mutual obstruction of phlegm and blood, stagnation of qi and phlegm; and close relationship with liver, spleen and kidney. Chinese medicine treatment cannot solve all thyroid nodules. For malignant thyroid nodules, the above methods are still needed. Postoperatively, Chinese herbal medicine can be used to regulate them. Clinical methods are often used to dredge the liver, regulate qi and phlegm, activate blood circulation, remove blood stasis and disperse nodules, etc., which have advantages in terms of effectiveness and safety. Personally, I think Chinese medicine is more effective for nodular goiter, but the effect can be seen only if it lasts for at least 3 months.