Chronic fibrosing thyroiditis

Introduction to chronic fibrotic thyroiditis Chronic fibrotic thyroiditis (chronic fibrousthyroiditis) is a relatively rare form of thyroid inflammation characterized by normal thyroid tissue replaced by a large number of dense fibrous tissues. The report by Riedel (1897) first described the disease, so it is also called Riedelthy thyroiditis (RT). RT also has many names, such as invasive fibrous thyroiditis, chronic woody thyroiditis, Riedel goiter, chronic sclerosing thyroiditis (chronic cleavage thyroiditis). Riedel's research under the microscope shows that RT has no features of malignant tumors, and simply removes the thyroid isthmus wedge, which can effectively alleviate the symptoms of tracheal compression. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: thrombosis

Causes of chronic fibrotic thyroiditis

(1) Causes of the disease

The etiology of RT is unclear. Some people think that RT is the result of autoimmune response. Another theory is that RT belongs to primary fibrotic disease and is part of systemic fibrosis. Evidence that RT is an autoimmune response is: 1 The proportion of anti-thyroid antibodies detected in RT patients can be as high as 67%. 2RT has pathological features of cell infiltration including lymphocytes and plasma cells. 3 focal vasculitis is another common pathological feature of RT. 4 patients with RT have a good effect on the treatment of adrenocortical hormone.

However, the patient's lymphocytes and serum complement are at normal levels, and it seems that RT is not an autoimmune response, and increased anti-thyroid antibody levels may be caused by other causes, such as thyroid tissue destruction and release during primary fibrosis. The body's immune system response, which leads to increased levels of anti-thyroid antibodies, can occur in approximately one-third of cases of RT, such as with retroperitoneal fibrosis, posterior fibrotic pseudotumor, sclerosing cholangitis, Fibrotic RT may also be associated with transforming growth factor-1 (TGF-1) in mediastinal fibrosis, pulmonary fibrosis, and the like.

(two) pathogenesis

1. The thyroid gland is normal or slightly enlarged, asymmetrical, the face is gray or yellowish white, the texture is hard and difficult to cut, and the extent and extent of the lesion are different, which may affect the entire thyroid gland, 33% to 50% is single Laterality, can also be limited to a part of a leaf, the boundary of the cut surface is unclear, the structure of the lobular leaves disappears, most of them only have a small amount of thyroid tissue containing colloid. The lesion often exceeds the capsule and invades the surrounding tissues and organs, including the neck muscle and trachea. Recurrent laryngeal nerve, carotid sheath, internal jugular vein, etc.

2. Microscopic examination of early lesions, a large number of lymphocytic infiltration can form lymphoid follicles, gradually thyroid follicles and epithelial cells shrink, thyroid tissue in the affected area is destroyed, lobular structure disappears, replaced by extensive glassy degeneration of fibrous lesions, There is a small amount of medium-sized lymphocytes, plasma cells (mainly producing IgA) infiltration, more around the blood vessels, sometimes visible eosinophilic aggregation, moderately venous wall inflammation wrapped by fibrosis is the main diagnostic point of the disease, fiber The number of small follicles in the tissue is reduced, or scattered follicles are scattered, follicular epithelial cells are atrophied, no eosinophilic changes, no diffuse lymphocytic infiltration, no lymphoid follicle formation, no giant cells and tuberculous granulation The swelling is formed, and the connective tissue in the lesion often directly invades the resting capsule and nearby muscles, fat, nerve tissue, etc. (Fig. 1).

Chronic fibrotic thyroiditis prevention

1. It is advisable to eat high-protein and nutritious food.

2. It is advisable to eat foods rich in vitamins and minerals.

3. It is advisable to eat high-calorie digestible food.

4. Avoid eating greasy and difficult to digest food.

5. Avoid eating fried, smoked, grilled, cold, and stimulating food.

6. Avoid eating high-salt and high-fat foods.

Chronic fibrotic thyroiditis complications Complications thrombosis

RT can cause venous blood stasis, vascular wall damage and hypercoagulable state leading to cerebral venous sinus thrombosis.

Chronic fibrotic thyroid symptoms common symptoms hoarseness, dyspnea, difficulty swallowing, dysthymia, goiter

RT can progress slowly after onset, and can still be static for many years after onset. It is accidentally discovered without clinical symptoms. RT can also suddenly start onset. At the time of physical examination, the gland of the thyroid gland is normal or slightly large, painless but quite hard. It can be as hard as wood or stone, usually bilaterally affected, and occasionally unilaterally.

The clinical manifestations of RT are often associated with localized compression symptoms. For example, after compression of the trachea and esophagus, dyspnea and difficulty in swallowing may cause hoarseness, speech loss or cough after the recurrent laryngeal nerve. If the thyroid tissue is completely fibrotic, it may appear. Hypothyroidism, fibrosis of the parathyroid glands can lead to hypofunction of the parathyroid glands, and rare subcutaneous tissue fibrosis can sometimes occur.

Examination of chronic fibrotic thyroiditis

Thyroid function depends on the degree of fibrotic thyroid tissue. Most patients have normal thyroid function. Laboratory tests for thyroid function are in the normal range, but about one-third of patients may have hypothyroidism, and occasionally patients have hyperthyroidism. ESR increased, but white blood cells did not increase, the detection rate of anti-thyroid antibodies was 67%, and eosinophils or eosinophils were visible in thyroid tissue.

1. CT scan and MRI CT scan can detect fibrotic thyroid tissue. MRI can detect diseased thyroid tissue on T1 weighted images (T1WI) and T2WI. Dynamic MRI can also find inflammatory cell infiltration and fibrosis. Lesion.

2.131I scans the diseased thyroid tissue as a cold nodule with no uptake function.

3. B-ultrasound showed homogeneity hypoechoic, and the boundary between thyroid tissue and adjacent tissue structure disappeared.

4. Positron emission computed tomography (PC) positron emission tomography (PET) with 18-fluoro-deoxyglucose (18F-FDG) for suspected fibrosis of other organs. ) Examination can reveal abdominal masses or thyroid masses with increased metabolic activity due to active inflammation of lymphocytes and plasma cells.

Diagnosis and diagnosis of chronic fibrotic thyroiditis

Middle-aged female patients, have painless goiter, hard texture, no tenderness, adhesion to surrounding tissues, and obvious compression symptoms. When the thyroid function is normal or slightly lower, the disease can be considered, thyroid radionuclide imaging It showed that the lesion was "cold nodule", indicating extensive fibrosis of the affected gland tissue.

Differential diagnosis

1. Thyroid cancer The symptoms of thyroid cancer are relatively late, and are related to the size of the cancer. There is often a swollen neck lymph node, but the pathological examination is still needed to confirm the diagnosis.

2. Subacute thyroiditis lesions are often bilateral, thyroid gland tenderness, tenderness, extra-glandular tissue without adhesion, and self-healing, are different from the disease.

3. Chronic lymphocytic thyroiditis is limited to goiter, does not invade surrounding tissues, has a tendency to hypothyroidism, TGAb, TMAb is often positive, can be identified with the disease.

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.