Thyroid nodules

Introduction to thyroid nodules Thyroid nodules can be single or multiple, and multiple nodules have a higher incidence than single nodules, but the incidence of single nodular thyroid cancer is higher. Thyroid nodules are complicated by various thyroid diseases, such as simple goiter, thyroiditis, thyroid tumors, etc., and their nodules are single or multiple, and there are clinically good and bad points. The benign mainly includes nodular goiter thyroid adenoma, malignant thyroid nodules are mainly thyroid cancer, and also include thyroid lymphoma and metastases. From the epidemiological point of view, thyroid-associated eye disease has a difference in susceptibility to population genes. In addition to the decrease in the proportion of males and females in elderly patients, the average female patient is 4-5 times that of male patients. The susceptibility and severity of disease may be related to genetic and environmental factors. HLA-DR histocompatibility loci (mainly related to T cell responses) are linked to thyroid-associated ocular diseases, but no exact genes have been found to cause disease. The cause of thyroid-associated eye disease is not clear, but thyroid-related eye disease, immune thyroid disease, and pre-tibial mucinous edema have been associated with immune mechanisms of cell regulation and humoral regulation. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: Diabetes, renal tubular acidosis, liver disease

Thyroid nodule etiology

Nodular goiter

Nodular goiter is a type of simple goiter that is mostly evolved from diffuse goiter and belongs to simple goiter. The main causes are as follows:

1, lack of iodine: is one of the main causes of endemic goiter. The iodine content in soil, water and food in epidemic areas is inversely proportional to the incidence of goiter. Iodized salt can prevent goiter and other facts can prove that iodine deficiency is an important cause of goiter. In addition, the body's increased demand for thyroid hormone can cause relative iodine deficiency, such as growth and development, pregnancy, breastfeeding, cold, infection, trauma and mental stimulation, etc., can aggravate or induce goiter.

2, caused by thyroid material: radish food contains thiourea-induced thyroid material, soy beans, cabbage also have some substances that can prevent the synthesis of thyroid hormone, causing goiter. The mineral content of calcium, magnesium and zinc in soil and drinking water is also related to the occurrence of goiter. In some areas, in addition to iodine, the above various elements are also lacking. In some areas, the incidence of goiter and the hardness of drinking water are Just proportional. Drugs such as potassium thiocyanate, potassium perchlorate, p-aminosalicylic acid, thiouracils, sulfonamides, phenylbutazone, colchicine, etc., can interfere with the synthesis and release of thyroxine, causing goiter.

3, hormone synthesis disorders: the cause of familial goiter is due to genetic enzyme defects, causing hormone synthesis disorders, such as the lack of peroxidase, deiodinase, affecting the synthesis of thyroxine, or the lack of hydrolase, making thyroid hormone It is difficult to separate from thyroglobulin and release into the blood, which can lead to goiter. This congenital defect is recessive.

4, high iodine: rare, may be local or sporadic distribution, the pathogenesis of excessive intake of iodine leads to excessive occupancy of TPO functional genes, thereby affecting tyrosine iodination, iodine organic process is blocked, thyroid Compensatory swelling.

5. Gene mutations: Such abnormalities include point mutations in exon 10 of the thyroglobulin gene.

Thyroid adenoma

A round or oval solid mass is visible to the naked eye, and the envelope is intact, the surface is smooth, and the texture is tough, ranging from a few millimeters to several centimeters. According to the histological morphology, it can be divided into three types: follicular type, papillary type and mixed type. Their common features are: most of them are single nodules, and the capsule is intact; the tumor tissue structure is obviously different from the surrounding thyroid tissue; the internal structure of the tumor It has relative consistency; the surrounding tissue is under pressure. However, they have different pathological manifestations. For example, follicular adenomas can be further divided into embryonic, fetal, glial and Hürthle cell types (eosophilic cells) according to their follicular size and the amount of gelatin. tumor). Papillary adenomas are rare (now known as papillary follicular adenomas), which are mostly cystic, so they are also called papillary cystadenoma. The nipple consists of a single layer of cubic or low columnar cells surrounding the blood vessels and connective tissue bundles. Thyroid adenomas with papillary structures have a greater malignant tendency and should be treated with caution. Any phenomenon of infiltration of the capsule or vascular invasion should be classified as papillary adenocarcinoma. If there is a 1-2 grade nipple branch, the tumor cells are arranged neatly, the heterogeneous nucleus is small, the schizophrenia is occasionally seen, and the capsule is intact, and the papillary adenoma can be temporarily treated, but the patient needs regular follow-up for recurrence or metastasis.

Thyroid cancer

The pathogenesis of thyroid malignancy is not clear, but its related factors include many aspects, mainly in the following categories:

1. Oncogenes and growth factors: Modern studies have shown that the occurrence of many animal and human tumors is associated with overexpression, mutation or deletion of protooncogene sequences.

2. Ionizing radiation: It has been found that external radiation of the head and neck is an important carcinogenic factor of the thyroid gland.

3, genetic factors: some medullary thyroid carcinoma is an autosomal dominant disease; in some patients with thyroid cancer, often ask family history

4. Iodine deficiency: As early as the beginning of the 20th century, it has been suggested that iodine deficiency can lead to thyroid tumors.

5. Estrogen: In recent years, studies have suggested that estrogen can affect the growth of the thyroid mainly by promoting the release of TSH from the pituitary and acting on the thyroid gland, because the level of TSH increases as the level of estrogen in the plasma increases. It is not clear whether estrogen acts directly on the thyroid gland.

Thyroglossal cyst

The thyroglossal duct is a congenital malformation associated with thyroid development. During the embryonic period, the thyroid gland occurs from the lower end of the thyroid gland that extends from the base of the mouth to the neck. The disease is more common in children under the age of 15 and twice as many as men.

Subacute thyroiditis

Often secondary to upper respiratory tract infections, with a typical medical history.

Thyroid malignant lymphoma

Primary thyroid lymphoma is a rare thyroid malignancy, accounting for 1% to 2% of thyroid cancer, male: female 1:3. Most of them are on the basis of Hashimoto's thyroiditis, and most of them are non-Hodgkin's lymphoma. It is the only tumor in the lymphoma that is predominantly female.

Thyroid metastases are rare. According to autopsy data, 4% to 24% of thyroids in patients with disseminated cancer are affected. The source of thyroid metastases is nothing more than three aspects: direct diffusion of adjacent structures (such as throat, esophagus, etc.), lymphatic metastasis (commonly known as breast cancer), and hematogenous metastasis (breast cancer, lung cancer, renal cell carcinoma, cutaneous melanoma). , fibrosarcoma, liver and biliary tract cancer, ovarian cancer, etc.).

Thyroid nodule prevention

Correct prevention

1, thyroid nodules patients should eat more spicy foods, such as pepper, chili oil.

2, daily to do 20-30 minutes of aerobic (outdoor) exercise, can improve the endurance of the heart and lungs, enhance physical fitness, not easy to fatigue when working.

3, thyroid nodules patients should sleep early every day, have enough sleep.

Thyroid nodule complications Complications, diabetic renal tubular acidosis, liver disease

If the thyroid nodules are not treated in time or the treatment is unreasonable, it may cause serious complications such as cardiovascular disease, diabetes, renal tubular acidosis, and liver disease.

Symptoms of thyroid nodules Common symptoms Nodules Dyspnea vocal cords numbness complexion blue-purple thyroid gland and smooth... hoarse hoarseness pharyngeal lumps under the laryngeal mass after delivery thyroid enlargement

Nodular goiter

The incidence of nodular goiter is higher in women than in men. It usually occurs in adolescence, and it often appears in the age of schooling in popular areas. Goiters vary in size and shape. In the initial diffuse enlargement, the sides are often symmetrical, and when the nodules are formed later, the bilateral sides are often asymmetrical. Nodular goiter can be associated with cystic changes. If there is intra-capsular hemorrhage, the nodule can rapidly increase in a short period of time and cause pain. The surface of the gland is generally flat and soft, and when swallowed, the gland moves up and down with the throat and trachea.

Nodular goiter is generally not functionally altered. The patient's basal metabolic rate is normal, but when the nodule is large, the trachea, esophagus, blood vessels, nerves, etc. can be compressed to cause the following symptoms:

1) Compression of the trachea: more common. Compression from one side, the trachea is displaced or bent to the other side, compression from both sides, narrowing of the trachea, difficulty breathing, especially in the retrosternal goiter. Long-term compression of the tracheal wall can cause the trachea to soften and cause suffocation.

2) Compression of the esophagus: rare. Only the retrosternal goiter may compress the esophagus, causing discomfort during swallowing, but does not cause obstructive symptoms.

3) Compression of the deep veins of the neck: it can cause difficulty in blood return to the head and neck. This condition is more common in the upper thoracic, large goiter, especially the retrosternal goiter. The patient's face was blue-purple edema with a pronounced expansion of the superficial veins of the neck and chest.

4) Compression of the recurrent laryngeal nerve: can cause vocal cord paralysis (mostly one side), the patient is hoarse. Compression of the cervical sympathetic ganglion chain can cause Horner syndrome, which is extremely rare.

Thyroid adenoma

Generally, no obvious symptoms are produced, and the pre-neck mass is often inadvertently found. The tumor grows slowly and does not change much in the long term. In the physical examination, a single lump is seen. It is round or oval, with a smooth surface, tough texture, clear boundary, no tenderness, and can be swallowed. If the tumor suddenly bleeds, the swelling of the tumor increases rapidly, with local pain and tenderness. These symptoms can disappear within a week. Large tumors can cause compression symptoms, and X-rays of the neck can be confirmed. In a few cases, functional autonomic thyroid adenomas can occur, with hyperthyroidism. If the tumor continues to increase, the activity is limited or fixed, the texture becomes hard, and there are compression symptoms such as hoarseness and difficulty in breathing. It is necessary to consider the possibility of tumor malignancy.

Thyroid cancer

Papillary carcinoma and follicular carcinoma have no obvious symptoms at the beginning, and the former may sometimes seek medical treatment due to swelling of the cervical lymph nodes. As the disease progresses, the mass gradually increases, the mass is hard, and the degree of movement of the mass is reduced when swallowing. The above symptoms of undifferentiated cancer develop rapidly and invade surrounding tissues. Late stage can produce hoarseness, difficulty breathing, and difficulty swallowing. The cervical sympathetic ganglia is compressed and can produce Horner syndrome. When the shallow branch of the cervical plexus is violated, the patient may have pain in the ear, pillow, shoulder, etc. There may be cervical lymph node metastasis and distant organ metastasis (lung, bone, central nervous system, etc.). In addition to cervical lumps, medullary carcinoma can cause diarrhea, palpitations, flushing of the face, and decreased blood calcium due to serotonin and calcitonin. For patients with a family history, attention should be paid to the possibility of multiple endocrine neoplasia syndrome type II (MEN-II).

Thyroglossal cyst

The thyroglossal duct is a congenital malformation associated with thyroid development. During the embryonic period, the thyroid gland occurs from the lower end of the thyroid gland that extends from the base of the mouth to the neck. The disease is more common in children under the age of 15 and twice as many as men. It is characterized by a circular mass of 1 to 2 cm in diameter in the midline of the anterior cervical region and below the hyoid bone. The boundary is cleared, the surface is smooth, the capsule is sexy, and it can move up and down with swallowing or stretching and shrinking the tongue.

Subacute thyroiditis

Subacute thyroiditis, also known as De Quervain thyroiditis or giant cell thyroiditis. The size of the nodule depends on the extent of the lesion and the texture is often hard. Often secondary to upper respiratory tract infections, with a typical medical history, including acute onset, fever, sore throat and significant thyroid pain and tenderness, pain often affects the affected ear, sacral occipital. Often, body temperature rises and erythrocyte sedimentation rate increases. In the acute phase, the rate of thyroid 131I decreased, mostly "cold nodules", but serum T3 and T4 increased, and the basal metabolic rate increased slightly. This separation is helpful for diagnosis.

Thyroid malignant lymphoma

It is more common in middle-aged and older women, mainly neck masses, and the rate of enlargement of tumors is inconsistent. Those with faster speed are similar to the clinical symptoms of undifferentiated thyroid cancer, which may be accompanied by dysphagia, such as compression of the trachea and even difficulty in breathing. Occasionally invaded the recurrent laryngeal nerve, causing hoarseness and local pain, partial growth is slow, and it is not easy to distinguish from nodular goiter and Hashimoto's disease.

Thyroid metastases are rare. According to autopsy data, 4% to 24% of thyroids in patients with disseminated cancer are affected. The source of thyroid metastases is nothing more than three aspects: direct diffusion of adjacent structures (such as throat, esophagus, etc.), lymphatic metastasis (commonly known as breast cancer), and hematogenous metastasis (breast cancer, lung cancer, renal cell carcinoma, cutaneous melanoma). , fibrosarcoma, liver and biliary tract cancer, ovarian cancer, etc.).

Thyroid nodule examination

Examination of thyroid nodules generally includes thyroid B-ultrasound, thyroid radionuclide scan, cervical X-ray examination, thyroid fine needle aspiration cytology, and thyroid function test.

Diagnosis of thyroid nodules

Nodular goiter

The main points of diagnosis of this disease are thyroid nodules and thyroid function is basically normal. T4 is normal or slightly lower, but T3 can be slightly higher to maintain normal thyroid function. The 131I uptake rate of thyroid is often higher than normal, but the peak time rarely appears early, and the T3 inhibition test can inhibit the reaction. Serum high-sensitivity TSH concentration is the best indicator for evaluating thyroid function, and serum TSH is often normal. It is not difficult to diagnose according to the characteristics of the throat and trachea moving up and down when swallowing; but if there is inflammation or malignant transformation, the goiter will adhere to the surrounding tissue, and this feature no longer appears. Patients with nodules should be differentiated from thyroid tumors and thyroiditis; nodules or cysts located in the thyroid isthmus can be misdiagnosed as thyroglossal cysts. Posterior sternal or intrathoracic goiter is sometimes difficult to distinguish from mediastinal tumors; it is not difficult to identify with aortic arch aneurysms, the latter has more pulsations.

Thyroid adenoma

1) Many patients have no symptoms, but they are found during physical examination. Some patients may have symptoms, such as rapid increase in a short period of time, it may be caused by cystic hemorrhage of adenoma, local pain and tenderness; if there is thyroid nodules in the past, suddenly increased rapidly and painlessly in recent days, should be considered Malignant changes are possible.

2) The obvious isolated nodules are the most important signs. The nodules are round or elliptical, with soft texture and smooth surface, moving up and down with swallowing.

3) Thyroid function test For thyroid adenoma, thyroid function may be normal, but when part of the adenoma presents autonomic function, TSH is inhibited.

4) B-ultrasound can display three basic images: cysts, mixed nodules, and substantial nodules, and provide anatomical information. B-ultrasound thyroid adenoma is difficult to distinguish from thyroid cancer. The information used to distinguish it mainly includes cystic solidity, echo, boundary, microcalcification, blood flow signal and so on.

5) Radionuclide scanning adenomas are mostly cold nodules in radionuclide scans, sometimes misdiagnosed as cancer; a few adenomas have the function of concentrating iodine, and the scan shows warm nodules; high-function adenoma scans When the time is displayed, "hot nodules" may be accompanied by hyperthyroidism.

6) Fine needle aspiration biopsy needle biopsy is a very effective diagnostic method, but sometimes the appropriate tissue is not obtained.

Thyroid cancer

1, thyroid function test: mainly the determination of thyroid stimulating hormone (TSH). The highly functional thermal nodules reduced by TSH are rarely malignant, so it is more important to treat hyperthyroidism. A normal or elevated thyroid nodule with TSH and a cold nodule or warm nodule with a reduced TSH should be further evaluated (eg, a biopsy, etc.).

2. Radionuclide scanning: Isotope scanning of radioactive iodine or strontium is an important means of determining the functional size of thyroid nodules. The results of the ECT examination included high functionality (higher uptake rate than surrounding normal thyroid tissue), functional or warm nodules (same rate as surrounding tissue) or no functional nodules (lower than thyroid tissue uptake) . Thyroid cancer generally has a low uptake rate, and high-function nodules ("hot nodules") have a low rate of malignant transformation.

3, B-ultrasound: Ultrasound is an important means to find thyroid nodules, and initially judge its benign and malignant, is the criterion for the implementation of fine needle aspiration biopsy (FNA), and is the most effective means of examination. All European and American guidelines refer to suspected malignant signs under ultrasound, including: hypoechoic nodules, microcalcifications, abundant blood flow signals, unclear boundaries, nodular height greater than width, solid nodules, and lack of halos .

4, needle smear cytology examination: needle aspiration biopsy includes fine needle aspiration biopsy and thick needle biopsy, the former is cytological examination, the latter is histological examination. For the suspected malignant thyroid nodules found by B-ultrasound, this method can be used to confirm the diagnosis. At present, fine needle aspiration biopsy is generally used, and the coincidence rate of diagnosis is high.

Subacute thyroiditis

Often secondary to upper respiratory tract infections, with a typical medical history, including acute onset, fever, sore throat and significant thyroid pain and tenderness, pain often affects the affected ear, sacral occipital. Often, body temperature rises and erythrocyte sedimentation rate increases. In the acute phase, the rate of thyroid 131I decreased, mostly "cold nodules", but serum T3 and T4 increased, and the basal metabolic rate increased slightly. This separation is helpful for diagnosis.

Thyroid malignant lymphoma

It is more common in middle-aged and older women, mainly neck masses, and the rate of enlargement of tumors is inconsistent. Those with faster speed are similar to the clinical symptoms of undifferentiated thyroid cancer, which may be accompanied by dysphagia, such as compression of the trachea and even difficulty in breathing. Occasionally invade the recurrent laryngeal nerve, causing hoarseness and local pain; part of the growth is slow, and it is not easy to distinguish from nodular goiter and Hashimoto's disease. The qualitative diagnosis of this disease mainly relies on fine needle aspiration cytology and surgical biopsy, which is easily confused with undifferentiated cancer which is mainly composed of small cells.

Thyroid metastases are rare, and the diagnosis depends mainly on clinical manifestations and histology.

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