Thyroid tuberculosis

Introduction to thyroid nodules Thyroid tuberculosis is a clinically rare tuberculosis. It was discovered in Lehrt's autopsy in 1857. It has been reported since then, but no large cases have been reported so far. In the 1175 thyroid surgery in Mayo Hospital in the United States, 21 cases (0.1%) of thyroid tuberculosis were found, and domestic reports were 0.4% to 0.76%. The disease is more common in young people and middle-aged patients between the ages of 20 and 50. Children can also develop the disease. The ratio of male to female is about 1:3 to 1:4. basic knowledge Proportion of disease: thyroid infection rate in tuberculosis patients is about 0.002% - 0.007% Susceptible people: no specific population Mode of infection: droplet spread Complications: hyperthyroidism

Causes of thyroid tuberculosis

Human tuberculosis (30%):

Thyroid tuberculosis can be divided into primary and secondary, secondary secondary, thyroid tuberculosis tissue is rich in blood supply, lymphatic dense, high oxygen content, generally not conducive to the growth and reproduction of Mycobacterium tuberculosis, but some people think The thyroid tissue is highly immune to Mycobacterium tuberculosis. The thyroid gland has an antagonistic effect on Mycobacterium tuberculosis. Only when the number of invading Mycobacterium tuberculosis is large, the virulence is large, and the immune function of the organism is reduced and the local resistance is weakened. Onset.

In recent years, studies have shown that the prevalence of extrapulmonary tuberculosis is significantly increased in human immunodeficiency, and the prevalence of extrapulmonary tuberculosis in HIV-positive patients with tuberculosis infection can reach 45% to 75%. Barner believes that 7% of the whole body Disseminated tuberculosis can involve the thyroid gland, primary thyroid tuberculosis, which means that the tuberculosis lesion is local to the thyroid gland, and there are no tuberculosis lesions in other parts of the body.

Route of infection (30%):

Most of the occurrence of thyroid tuberculosis is accompanied by tuberculosis, but there is no clinical symptoms. The main route of infection is blood-borne infection, most of which are miliary tuberculosis. Therefore, thyroid tuberculosis is a local manifestation of systemic tuberculosis, primary thyroid. Tuberculosis is rare, and the second route of infection is that the thyroid gland is directly affected by the tuberculosis of adjacent organs. Again, it is through lymphatic infection, and early lymphatic tuberculosis passes through the lymphatic to thyroid tissue.

Pathological type (30%):

There are three main types of pathological types of thyroid tuberculosis:

(1) Acute miliary type: This type is rare. It is part of the dissemination of systemic tuberculosis blood. The thyroid gland is densely distributed, with a uniform distribution of round, miliary-sized gray-white tuberculous nodules.

(2) cheese type: thyroid nodules nodules are cheese-like, necrotic, forming a cold abscess, thyroid tissue fibrosis forms a wall of abscess, and can adhere to the surrounding tissue, palpation is sexy, sometimes broken Sinus.

(3) proliferative type: the thyroid gland is nodular and swollen, the texture is hard, and the lesion is composed of scattered hyperplasia, tuberculous granuloma, and fibrous tissue proliferation around it.

Thyroid tuberculosis prevention

According to different symptoms, there are different dietary requirements, ask the doctor specifically, and set different dietary standards for specific diseases.

Thyroid tuberculosis complications Complications

Can be added and subtracted, hyperthyroidism or tuberculosis to other parts of the transfer.

Symptoms of thyroid tuberculosis Common symptoms Fatigue, high heat, loss of appetite, calcification, abscess, heat, goiter, night sweats, weight loss, low fever

Most of the onset is slow, the disease is long, the symptoms are not significant, and there are many extrathyroid tuberculosis, but it is not always possible to find tuberculosis outside the thyroid gland.

Systemic symptoms

Thyroid tuberculosis may have symptoms of tuberculosis, mainly characterized by low fever or relaxation type hyperthermia, less with chills; patients with fatigue and loss of appetite, night sweats, weight loss and so on.

2. Local symptoms and signs

Different types of thyroid tuberculosis have slightly different local symptoms and signs.

(1) Miliary type: It is a part of systemic tuberculosis, and the onset is urgent. The other parts of the body have tuberculosis at the same time, and the thyroid gland is not swollen. However, miliary tuberculous nodules can be found in the thyroid tissue, which cannot be found before birth. Most of them are sick. Confirmed when the solution, so there is no clinically significant diagnostic significance.

(2) cheese type: clinically more common, thyroid enlargement, painless mass, the time varies from 1 month to more than 10 years, mostly isolated nodules, the surface is not smooth, the boundary is unclear, Can move up and down with swallowing, such as the formation of cold abscess, the mass of the mass appears, mild tenderness, and the heavy body and the surrounding tissue or organ are bonded into a block, fixed.

(3) Diffuse fiber type: the thyroid gland is obviously swollen, the surface is not smooth, it is uneven, it is nodular, and the texture is hard. It is very similar to goiter or chronic thyroiditis; the heavy one is sticky with the surrounding tissues or organs and even the skin. Misdiagnosed as thyroid cancer.

Examination of thyroid tuberculosis

Blood routine

Hemoglobin in patients with thyroid tuberculosis may be mildly or moderately reduced, and white blood cell counts are mostly normal.

2. Erythrocyte sedimentation rate

During the active period of thyroid tuberculosis, the erythrocyte sedimentation rate increases.

3. Tuberculin test

Intradermal injection of 1:10000 old tuberculin 0.1ml in the forearm, observed once every 24, 48, 72h, strong positive reaction; or take tuberculin pure protein derivative (PPD) skin test solution 50U / m1 0.1 ml of the diluted product was injected into the flexor of the forearm, and observed once at 24, 48, and 72 h, and the reaction was positive.

4. Thyroid function test

T3, T4, FT3, and FT4 were measured normally or under low.

5. Fine needle aspiration cytology (FNAC)

It is currently believed that fine needle aspiration cytology (FNAC) is the most reliable diagnostic method, and thyroid epithelial cell necrosis and Langhans giant cells can be seen under the microscope.

Mondal (1995) performed FNAC examination on 11565 cases of thyroid disease, and found 18 cases of thyroid tuberculosis or tuberculous thyroiditis, 12 cases of 18 cases, and 6 cases of males, 4 of which were treating tuberculosis, and no other tuberculosis, all The patient's thyroid gland has induration, radioactive iodine scan has plaques with significantly reduced density, cytology found epithelial cell necrosis, Langhans giant cells, acid-fast bacilli negative in 12 cases, acid-fast bacilli culture in 11 positive, acid-resistant One case of bacillus culture is negative, which may be related to the treatment of tuberculosis with anti-tuberculosis drugs. Therefore, if thyroid tuberculosis is suspected, FNAC is an effective diagnostic method. At present, most of them advocate puncture under the guidance of B-ultrasound and to the nodules. Take multiple directions.

6. Tissue section pathological examination

Tuberculous nodules, cheese-like necrotic tissue and cold abscess formation were seen.

7. Thyroid B-ultrasound

The location, size, cystic or substantial of the nodule can be determined, but the nature of the mass cannot be determined.

8. Radionuclide scanning

On the nucleus scan of the thyroid gland, the nodules of thyroid tuberculosis can be characterized as non-functional cold nodules, but it should be noted that thyroid cysts, intraepithelial hemorrhage, thyroid cancer and other thyroid diseases can also express cold nodules.

Diagnosis of thyroid tuberculosis

Diagnostic criteria

Thyroid tuberculosis lacks special clinical manifestations, and early diagnosis is not easy.

1. Basis for preliminary diagnosis

Even if thyroid tuberculosis lacks typical clinical symptoms, there are some clinical manifestations that can be used as a basis for initial diagnosis:

(1) Symptoms of tuberculosis poisoning: such as night sweats, loss of appetite, and weight loss.

(2) There is a history of tuberculosis: such as lymphatic tuberculosis, tuberculous pleurisy, tuberculosis calcification, kidney tuberculosis, bone tuberculosis, etc.

(3) Sometimes it can be expressed as hyperthyroidism or hypothyroidism.

Wegelin believes that in the acute phase of thyroid tuberculosis, a large amount of colloid is synthesized by normal thyroid tissue and secreted to cause hyperthyroidism. Therefore, when there is a thyroid hard joint and hyperthyroidism, it is necessary to consider whether there is a possibility of thyroid tuberculosis.

2. Basis for diagnosis

It is now believed that thyroid tuberculosis can be diagnosed when two of the following three conditions are met:

1 find tuberculosis in the thyroid tissue;

2 pathological examination of thyroid tissue sections can clearly see the formation of tuberculous nodules, caseous necrotic tissue, cold abscess;

3 There are primary tuberculosis lesions outside the thyroid tissue. The first two need to be confirmed by pathological sections of FNAC or surgical specimens.

Wu Zhuanghong had treated 1 case of thyroid tuberculosis, had thyroid induration but no tuberculosis, and many auxiliary examinations failed to indicate thyroid tuberculosis until a frozen section was taken during surgery to make a correct diagnosis. Huguette et al also had similar findings. Highly suspected cases of thyroid tuberculosis, treated with anti-tuberculosis drugs, including isoniazid, rifampicin, ethambutol and pyrazinamide, after 1 month, the thyroid mass has not shrunk, pathological examination after surgical removal of the thyroid mass, Only confirmed as thyroid tuberculosis.

Differential diagnosis

The lack of specificity in the clinical manifestations of thyroid tuberculosis, combined with the previous history of no tuberculosis, is not easy to diagnose before the pathological diagnosis is obtained. The clinically necessary thyroid diseases are:

Subacute thyroiditis

The disease occurs in women. It is caused by rupture of thyroid follicles after viral infection. Glue overflows, and the course of disease is longer. Radionuclide scanning can show cold nodules. It is difficult to distinguish with thyroid tuberculosis. After treatment with thyroxine or levothyroxine. Symptoms can be alleviated and have a tendency to heal.

2. Chronic thyroiditis

Mainly lymphatic thyroiditis and invasive fibrous thyroiditis, especially the latter can show hard thyroid nodules, difficult to distinguish with proliferative thyroid tuberculosis.

3. Thyroid adenoma or thyroid cancer

It is not uncommon for thyroid cancer to metastasize to cervical lymph nodes and misdiagnosed as lymphatic tuberculosis. Conversely, cervical lymphatic tuberculosis and thyroid cancer occur simultaneously, and some thyroid tuberculosis with cervical lymphatic tuberculosis is misdiagnosed as cancer. Rankin analyzed 21 cases misdiagnosed. When thyroid tuberculosis was found, 12 cases were misdiagnosed as toxic diffuse thyroid, 4 cases were misdiagnosed as thyroid adenoma, 4 cases were misdiagnosed as chronic thyroiditis, 1 case was misdiagnosed as thyroid cyst and hemorrhage, and 6 cases of thyroid tuberculosis reported by Gaofang were under operation. All were misdiagnosed, including 4 cases of thyroid tumor, 1 case of thyroid cancer, and 1 case of acute suppurative thyroiditis.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.