Overview
Most goiter caused by iodine deficiency, iodine overdose, heredity and other factors have no obvious symptoms, some of which may be manifested as thickening of the neck compared with the previous, dysphagia, dyspnea, etc. Mildly asymptomatic people caused by iodine deficiency, iodine overdose, goiter-causing substances, heredity and other factors can be left untreated for the time being; for those who have obvious enlargement, accompanied by symptoms of compression, can be treated with surgical procedures, etc.
Definition
Simple goiter refers to compensatory enlargement of the thyroid gland not caused by inflammation or tumor, which may be diffuse or nodular, and thyroid function is generally within the normal range.
Classification
Classification according to pathogenesis
Endemic goiter
If the prevalence of simple goiter is more than 5% of children in a region, it is called endemic goiter.
Sporadic goiter
Sporadic goiter occurs during puberty, pregnancy, lactation, and menopause, and is usually due to a temporary increase in thyroxine requirements.
Morbidity
Endemic goiter is widely distributed all over the world, mainly found in mountainous areas far from the sea and at high altitude. In China, it is mainly found in the southwest, northwest and north China, etc. Due to the nationwide census and prevention of endemic goiter, the incidence of this disease in China has been significantly reduced.
Sporadic goiter occurs in adolescence, pregnancy, lactation and menopause.
Causes
Causes
Iodine deficiency
Iodine deficiency is the main factor causing endemic goiter.
Mountainous and highland areas are far away from the sea and the iodine content in the soil is low, so the drinking water and food in these areas often lack sufficient iodine content.
Iodine is the raw material for the synthesis of thyroid hormones. When iodine deficiency occurs, thyroid tissue undergoes compensatory hyperplasia, resulting in goiter.
Goiter-causing substances
Common foods such as cabbage and cassava can release thiocyanate which can inhibit thyroid peroxidase and cause goiter.
The amount of calcium, magnesium, zinc and other minerals in the soil and drinking water is also related to the occurrence of goiter.
Compounds in industrial wastewater such as phenols, phthalates, pyridines and polyaromatic hydrocarbons are also goitrogenic.
Drugs such as potassium thiocyanide, potassium perchlorate, p-aminosalicylic acid, sulfonamides, potexin, colchicine, and lithium salts can inhibit the concentration or organification of iodide ions, and large quantities of iodide can inhibit the synthesis and release of thyroid hormones, which in turn can cause goiter.
High iodine
Less common than low iodine, long-term consumption of water containing high iodine and long-term use of iodine-containing drugs may also cause goiter.
Hormone Synthesis Disorders
Abnormalities in any of the steps in the synthesis of thyroxine can cause hormone synthesis disorders.
Lack of peroxidase and deiodinase may affect the synthesis of thyroid hormone; lack of hydrolytic enzyme may make it difficult to separate thyroid hormone from thyroglobulin and release it into the blood, which may lead to goiter.
Genetic mutations
Includes genetic abnormalities involving proteins involved in thyroid hormone synthesis, such as mutations in thyroglobulin, sodium/iodine cotransporter, and thyroid peroxidase genes.
Symptoms
Major Symptoms
Most patients are asymptomatic and may recognize a thickening of the neck.
The thyroid gland is often mildly or moderately diffusely enlarged, with a smooth surface, soft texture and no tenderness.
When goiter is severe, there may be compression symptoms.
Tracheal compression, there may be laryngeal constriction, chronic irritating dry cough, breathlessness, dyspnea and so on.
Esophageal compression, can be manifested as dysphagia.
Compression of the recurrent laryngeal nerve, early hoarseness, spasmodic cough, late loss of voice can occur.
Cervical sympathetic nerve compression, can appear ipsilateral pupil dilation, severe cases of Horner’s syndrome, manifested as the lower limit of the eyeball, pupil narrowing, eyelid ptosis.
A goiter located behind the sternum or in the thoracic cavity may cause superior vena cava compression syndrome, causing unilateral edema of the head, face, or upper extremities.
Consultation
Department of Medicine
Endocrinology
If you have a thick neck, hoarse voice, or difficulty swallowing, it is recommended that you consult a doctor promptly.
Thyroid Surgery
If you experience any of the above symptoms, you can also consult the Department of Thyroid Surgery.
Preparation
Information on registration, preparation of documents, and frequently asked questions.
Tips for the doctor
To make it easier for the doctor to examine you, try not to wear high-collared clothing or jewelry such as necklaces.
Preparation Checklist
Symptom list
Pay particular attention to the time of onset of symptoms and special manifestations.
Do you feel that your neck has become thicker than before?
Do you have difficulty breathing, swallowing, hoarseness, coughing, etc.?
Is there edema of the head, face or upper limbs?
When did the above symptoms appear?
List of medical history
Is there any history of long-term residence in iodine-deficient areas, such as mountainous and highland areas?
Do you consume iodized salt?
Have you been taking iodized drugs, such as amiodarone, for a long time?
Does anyone in the family have goiter?
Checklist
Test results in the last six months, which can be brought to the doctor’s office.
Laboratory tests: thyroid function test, urine iodine, etc.
Imaging tests: thyroid ultrasound, etc.
Medication list
Medication used in the last 3 months, if available in boxes or packages, bring with you to the doctor’s office
Goiter-causing medications: e.g. potassium thiocyanide, potassium perchlorate, sulfonamides, prednisone, colchicine, etc.
Diagnosis
Diagnosis is based on
Medical history
Long history of living in iodine-deficient areas such as mountains and plateaus.
Long-term consumption of uniodized salt.
Long-term consumption of iodine-containing drugs, such as amiodarone.
Family history of simple goiter.
Clinical manifestations
Most of the patients have no obvious symptoms, but may realize that their necks are thicker than before.
The thyroid gland is often mildly or moderately diffusely enlarged, with smooth surface, soft texture, no pressure pain, and nodules in the late stage.
When goiter is severe, it may cause compression symptoms, such as compression of the trachea, dry cough, breathlessness, dyspnea, compression of the esophagus, dysphagia, compression of the recurrent laryngeal nerve, hoarseness.
Laboratory Tests
Thyroid function tests
Thyroid function is determined by the levels of thyroid stimulating hormone (TSH), serum total thyroxine (TT₄), serum total triiodothyronine (TT₃), and serum free thyroid hormone.
Thyroid function is mostly normal in patients with simple goiter.
In iodine-deficient patients, TT4 may be mildly decreased and the T3/T4 ratio may be increased.
Serum thyroglobulin measurement
Serum thyroglobulin (Tg) levels are normal or elevated, with the degree of elevation positively correlating with the size of the goiter.
Urine Iodine Measurement
Urinary iodine ion content can be measured, which helps to evaluate iodine nutritional level.
Urinary iodine less than 100μg/L is considered iodine deficiency.
Thyroid Peroxidase Antibody Measurement
Helps to rule out autoimmune thyroiditis.
Imaging
Thyroid ultrasonography
With the advantages of convenience, speed and non-invasiveness, it is a commonly used thyroid examination method.
The examination can observe the size of the thyroid gland and the presence or absence of thyroid nodules, as well as the specific features of the nodules, including: size, number, borders, shape, echogenicity, presence or absence of calcification and blood flow.
Iodine 131 Nuclear Scan
It can be used to assess the functional status of the thyroid gland and can also clarify whether the upper mediastinal mass is thyroid tissue.
Precautions: Drink plenty of water after the examination to facilitate the elimination of the contrast agent.
CT, MRI
It is mainly used to clarify the relationship between goiter and neighboring tissues, and the continuation of goiter behind the sternum.
Precautions: Metal objects on the body, such as necklaces and earrings, should be removed during the MRI examination.
Barium esophagography
It can clarify the degree of esophageal compression.
Precautions: Fasting from food and water for 8 hours before the examination.
Other Tests
Lung function test: can be used for whether there is compression in the trachea.
Fine needle aspiration cytology: helps to clarify the nature of goiter.
Differential Diagnosis
Subacute thyroiditis
Similarities: Both may present with enlarged thyroid gland.
Differences: Subacute thyroiditis is usually associated with pain in the thyroid gland, which is aggravated by swallowing, and may be accompanied by general malaise, muscle pain, fever and malaise.
Hashimoto’s thyroiditis
Similarities: Both may present with an enlarged thyroid gland.
Differences: Hashimoto’s thyroiditis is an autoimmune thyroiditis and may be associated with positive anti-thyroid peroxidase antibodies.
Hyperthyroidism
Similarities: Both can have an enlarged thyroid gland.
Differences: Patients with hyperthyroidism may also have systemic symptoms, including weight loss, palpitations, and hand tremors, which are not usually present in patients with simple goiter.
Treatment
Most goiters in adolescents go away on their own.
Mild asymptomatic goiter can be left untreated for the time being, with close observation of clinical symptoms and regular follow-up visits to assess the condition.
For patients with obvious goiter with compression symptoms, drug and surgical treatments can be taken according to the specific situation.
General treatment
Iodine supplementation can be given to those with simple iodine deficiency, and the thyroid gland can be retracted to different degrees after supplementation.
Consumption of iodized salt is an effective and relatively safe method. Generally speaking, diffuse goiter can shrink back to normal after 6 to 12 months of continuous iodine supplementation, with a few cases taking several years.
Medication
Thyroid hormone
Thyroid hormone can be applied to those with obvious goiter and higher than normal thyrotropin.
The commonly used drug is levothyroxine sodium.
It is usually started at a small dose, and the dosage needs to be adjusted under the supervision of a doctor, and the thyroid function needs to be monitored during the treatment.
Adverse effects such as arrhythmia, headache, muscle weakness, insomnia and excessive sweating may occur if the individual’s tolerated dose is exceeded or if an overdose is taken.
Surgery
Indications
Large glands that affect life, work and aesthetics.
Those who develop nodular goiter and compress the trachea, esophagus, etc., with localized compression symptoms.
If the nodular goiter is suspected to be malignant.
Combined with hyperthyroidism.
Post sternal goiter.
Surgical approach
Depending on the location, size, number and degree of hyperplasia of the nodules, an appropriate surgical approach will be chosen.
Commonly used surgical methods include resection of thyroid nodules, major thyroidectomy, and total thyroidectomy.
Post-operative precautions
After surgery, pay attention to wound hygiene, avoid touching and sterilize regularly.
After surgery, you need to learn the correct way of coughing, coughing should be soothing, avoiding violent coughing.
Strenuous activities, especially neck activities, are not recommended after surgery; the neck can be moved gradually after the wound has healed.
After surgery, it is advisable to eat a light diet and avoid stimulating food to prevent coughing.
Radioactive iodine 131 treatment
Iodine 131 treatment can be considered for some patients with oversized glands who cannot tolerate surgery and recurrence after surgery.
Iodine 131 treatment is reliable in reducing the size of the thyroid gland, and the size of the thyroid gland gradually shrinks after treatment, with the majority of patients being able to reduce the size of the thyroid gland by about 50% after 6 to 12 months.
Hypothyroidism and transient thyrotoxicosis may occur after iodine 131 treatment, therefore, thyroid function should be closely followed up, and thyroxine should be added in time if necessary, and the dose should be gradually adjusted to the appropriate dose according to the thyroid stimulating hormone level in the follow-up.
Prognosis
Cure
The prognosis of most cases of simple goiter is good, but a few cases may develop into nodular goiter or thyroid function abnormality.
Hazards
If the goiter is obvious, it may cause symptoms such as neck enlargement, difficulty in swallowing and breathing, etc., which may affect the appearance and life.
Daily
Daily management
Dietary management
Iodine-deficient people can supplement iodine-rich foods, such as kelp, seaweed, nori, etc. Use iodized salt in cooking.
Avoid excessive consumption of foods that inhibit thyroid hormone synthesis such as cabbage and cassava for a short period of time.
Eat a sensible diet and limit the use of cholesterol-rich foods such as cream, animal brains and offal.
Life Management
Adopt good living habits, regular work and rest, and avoid exertion.
Exercise moderately to improve physical fitness.
Maintain a good state of mind and avoid bad emotions such as fear and anxiety.
Dress in loose-fitting clothes and avoid clothes with too tight a collar.
Disease monitoring
Pay attention to perceive whether there is pain in the thyroid area, whether there is difficulty in swallowing, breathlessness, hoarseness and other symptoms. If symptoms occur, seek medical attention.
Sense whether the neck continues to increase in size and seek medical attention if there is any discomfort.
Follow-up and review
Regularly review thyroid function and thyroid ultrasound according to your doctor’s instructions.
Prevention
For endemic goiter caused by iodine deficiency, iodine supplementation is the mainstay of prevention and treatment of the disease.
Since increased urinary iodine excretion and increased iodine demand by the fetal thyroid gland in pregnant and lactating women may lead to a relative deficiency of maternal thyroid hormones, an iodine intake of 250 μg per day is recommended for pregnant and lactating women, i.e., frequent consumption of iodine-rich seafood on top of iodized salt.
For patients with abnormal thyroid function, specific iodine intake needs to be clarified under the guidance of a doctor.