What are Thyroid Nodules?

A thyroid nodule is a mass in the thyroid that moves up and down with the thyroid gland as it swallows. It is a common clinical condition and can be caused by a variety of causes. There are many clinical thyroid diseases, such as thyroid degenerative changes, inflammation, autoimmunity, and new organisms, which can manifest as nodules. Thyroid nodules can be single or multiple. Multiple nodules have a higher incidence than single nodules, but single nodules have a higher incidence of thyroid cancer.

Basic Information

English name: thyroid nodule
Visiting department: surgical

Multiple groups: Women and the elderly
Common symptoms: The thyroid can be enlarged and can lump up

Causes of thyroid nodule

Thyroid nodules can be caused by a variety of causes.

Proliferative nodular goiter

Iodine intake is too high or too low, goiter-causing substances are consumed, goiter-causing drugs or thyroid hormone synthase deficiency are taken.

2. Tumorous nodules

Benign thyroid tumors, papillary thyroid tumors, follicular cell carcinoma, medullary thyroid carcinoma, undifferentiated cancer, lymphoma, and other thyroid follicular and non-follicular cell malignancies, as well as metastatic cancers.

3. Cyst

Nodular goiter, adenoma degenerative and old hemorrhagic spot cystic change, thyroid cancer cystic change, congenital thyroid hyoid cyst, and residual cyst caused by fourth gill cleft.

4. Inflammatory nodules

Acute purulent thyroiditis, subacute purulent thyroiditis, and chronic lymphocytic thyroiditis can all appear in the form of nodules. In rare cases, thyroid nodules are caused by tuberculosis or syphilis.

Clinical manifestations of thyroid nodules

Nodular goiter

More common in women and the elderly. In the case of relatively insufficient thyroid hormone in the body, the pituitary gland secretes increased TSH. Under the long-term stimulation of this increased TSH, the thyroid gland causes increased thyroid unevenness and nodular changes after repeated or continuous proliferation. Nodules may have bleeding, cystic changes, and calcifications. The size of the nodule can range from a few millimeters to a few centimeters. The main clinical manifestations are goiter, multiple nodules of varying sizes can be palpated on palpation, and the texture of the nodules is mostly of medium hardness. A few patients can only reach a single nodule, but it is used for thyroid imaging or surgery. Often, multiple nodules are found. The clinical symptoms of the patient are not many. Generally, there is only anterior neck discomfort, and most of the thyroid function tests are normal.

2. Nodular Toxic Goiter

The onset of this disease is slow. It often occurs in patients who have had nodular goiter for many years. They are more than 40-50 years old. They are more common in women and may be accompanied by symptoms and symptoms of hyperthyroidism, but the symptoms of hyperthyroidism are generally mild. , Often atypical, and generally do not occur with invasive exophthalmos. A thyroid smooth palpation can be palpated on palpation. The border is clear and the texture is hard. It moves up and down with swallowing. There is no vascular noise in the thyroid. A thyroid function test showed an increase in thyroid hormone in the blood, caused by a functionally autonomous nodule, and a nuclide scan showed a "hot nodule."

3. Inflammatory nodules

There are two types of infectious and non-infectious, the former is mainly subacute thyroiditis caused by viral infection, and other infections are rare. In addition to thyroid nodules clinically, methylene inflammation is accompanied by fever and local thyroid pain. The size of the nodule depends on the extent of the lesion, and the texture is tough; the latter is mainly caused by autoimmune thyroiditis, which is more common in For young women, the patients have less conscious symptoms, which can affect multiple or single nodules during the examination. The texture is hard and tough, and there is less tenderness. Thyroid function tests show that thyroglobulin antibodies and thyroid microsomal antibodies are often strongly positive.

Thyroid nodule examination

Serological examination

Abnormal thyroid function cannot rule out thyroid cancer, but it may be small, with hyperthyroidism or reduced TSH, all suggesting autonomous functional thyroid adenomas, nodules, or toxic multinodular goiters. Patients with medullary thyroid cancer have elevated serum calcitonin levels, but they need to be stimulated with pentagastrin and calcium in the early stages of C cell proliferation.

2. Nuclide scanning

Scanning has less significance in distinguishing benign and malignant lesions. Most benign and malignant parenchymal nodules are low-function relative to the surrounding normal glandular tissues. Therefore, it is found that cold nodules are rarely specific, and overlapping uptake of nuclide by surrounding normal glandular tissues can miss small nodules. Many thyroid cancers can take Tc, so there are still some cases of cancer in thermal nodules.

3. Ultrasound diagnosis

Ultrasound is reliable in diagnosing cystic lesions. It has little value for distinguishing benign and malignant. However, it is significant in determining the size of the nodule, identifying the location of the nodule, and guiding the puncture.

4. Other nuclide inspection

Positron emission tomography (PET) can be used to detect nodular thyroid lesions and identify benign and malignant tumors. Proton magnetic resonance seems to identify normal glandular and cancerous tissues.

5. Fine needle aspiration cytology

It is very helpful for nodule treatment. The widespread application of this method greatly reduces unnecessary thyroid surgery, improves the detection rate of intraoperative malignant tumors, and reduces the cost of thyroid nodule treatment. The accuracy of fine-needle aspiration cytology is 70% to 90%, which is related to the experience of puncture and cytology diagnosis.

6. Fine needle aspiration cytology (FNAC)

There was a 90% agreement between the FNAC results and the surgical pathological results. There is only a 5% false negative rate and a 5% false positive rate. Of course, the compliance rate depends on the success rate of the operator, and the difference is large.

7. X-ray examination of the neck

Those who have fine or grit-like calcifications on the nodules may be grit bodies of papillary carcinoma. Large, irregular calcifications can be seen in degenerative nodular goiter or thyroid cancer. If there is infiltration or deformation in the trachea, it indicates a malignant lesion.

8. Determination of thyroid function

Functionally autonomous toxic nodules are mostly hyperthyroidism. Subacute thyroiditis may also be hyperactive in the early stages. Chronic lymphocytic thyroiditis may be normal, hyperactive, or reduced.

Diagnosis of thyroid nodules

1. Serum thyroid stimulating hormone and thyroid hormone

All patients with thyroid nodules should be tested for serum TSH and thyroid hormone levels. Increased serum thyroid hormone levels and decreased TSH suggest that thyroid nodules are autonomous and highly functional nodules, with the majority being benign nodules. Most patients with thyroid cancer have normal thyroid function.

2. Determination of serum calcitonin levels

Patients with a family history of medullary thyroid cancer or a family history of multiple endocrine adenomas should be tested for serum calcitonin levels in a basal or stimulated state. Such as a significant increase in serum calcitonin levels suggest that the nodule is medullary thyroid cancer.

3. Ultrasound of thyroid

High-definition thyroid ultrasound is the most sensitive method for evaluating thyroid nodules. It can identify the properties of thyroid nodules, such as the location, shape, size, number of nodules, edge status of the nodules, internal structure, echo form, blood flow status, and cervical lymph node status. It has reliable diagnostic value for thyroid cystic nodules. It can also be used for FNAC examination under ultrasound guidance.

4. Thyroid nuclide imaging

The diagnostic sensitivity for thyroid nodules is not strong, but this test method is characterized by the ability to evaluate the function of the nodules. Nodules are divided into "hot nodules", "warm nodules" and "cold nodules" according to their ability to absorb radionuclides.

Thyroid Nodule Treatment

Substantial single nodule

The nuclide scan is a single thyroid nodule with a hot nodule, which is less likely to become cancerous. Cold nodules often require surgery. Solitary nodules that develop rapidly and have a hard texture, or those with swollen neck lymph nodes or children, may have large malignancy and should be treated as soon as possible.

2. Multinodular Goiter (MNG)

Traditionally, MNG is less likely to develop cancer than single nodules. And using high-resolution ultrasonography, it was found that many patients who had a single nodule were actually multiple nodules, and now there is not much difference in the incidence of cancer between them. Therefore, the treatment of MNG must first exclude malignancy. If sTSH decreases, it indicates hyperthyroidism. If FNA is diagnosed as malignant or suspected malignant, surgery should be performed.

3. Intangible nodules

In recent years, due to the development of B-ultrasound, CT, and MRI, small invisible thyroid nodules can be unexpectedly found during other examinations. This condition is more common in the elderly. Generally, there is no history of thyroid disease and no risk factors for thyroid cancer. Nodules are less than 1.5cm. Only follow-up observation is needed. If the nodules are larger than 1.5cm, FNA can be done under the guidance of ultrasound. Learn the results and process them further.

4. Radiation Nodule

Those who receive radiation therapy for the head and neck are prone to thyroid cancer, as early as 5 years after radiation and as late as 30 years after radiation. Patients with thyroid nodules after radiotherapy for head and neck should be diagnosed with FNA.