Table of Contents
Definition of Goiter
Goiter as a symptom
The term “goiter” is purely descriptive in nature and thus reveals nothing about the pathogenesis or the functional status of the thyroid gland. Therefore, goiter is a symptom. So, it primarily describes the enlargement of the thyroid and refers by means of other terms to the type and location of that very enlargement.
When talking about a goiter, we mean the thyroid gland volume exceeding the gender and age normal range. Women have a thyroid volume of more than 18 ml, men – a bit more than > 25 ml.
Epidemiology of Goiter
Goiter — Common finding
Thyroid enlargement and thyroid nodules are frequent findings in practice. Sonographically 20 % of the 25-year olds and 50 % of the over 50-year olds have a goiter. The prevalence of nodular thyroid abnormalities compounds 20 % more among the over 50-year-olds (Böhm 2009). Overall, women are more often affected than men.
Classification of Goiter
Classification of goiter-size stages by WHO
|Ia||Palpable goiter, not visible when bending the head back, solitary nodule|
|Ib||Palpable goiter, only visible when bending the head back|
|II||Visible and palpable goiter even without the reclination of the head|
|III||Goiter visible at a distance with obstruction of the trachea and esophagus, or spreading behind the sternum|
Classification of goiter after thyroid hormone function
|Euthyroid||Thyroid hormone level in the normal range|
|Hypothyroidism||Decreased thyroid hormone level|
|Hyperthyroidism||Increased thyroid hormone level|
Etiology and Pathogenesis of Goiter
Multiple causes of goiter
The causes of goiter occurrence are manifold. The most common cause in industrialized countries is often an endemic iodine deficiency (alimentary iodine deficiency). Other possible causes are:
- Immune thyreopathies (Graves’ disease, Hashimoto’s thyroiditis)
- Medications (phenytoin, lithium, anti-thyroid drugs, carbimazole)
- Neoplastic production of TSH
- Iodine failed use
Symptoms of Goiter
Non-specific symptoms as the first signs of goiter
Most goiters are asymptomatic. A visible thyroid enlargement can only be seen from a volume of about 40 ml. The enlargement of the thyroid can be accompanied with a mechanical impairment of organs and tissues bordering on it (tracheal and/or Esophagus compression).
The extent to which this goiter is symptomatic essentially depends on its localization. In the case of retrosternal or retrotracheal growth, it may restrict the larynx and trachea in their anatomical position so much that dysphagia, dyspnea and hoarseness may occur.
In the case of the esophagus compression, the patient complains about globus or pressure sensation in the throat, furthermore, problems with swallowing.
|Common Symptom||Restricted Organ/Tissue|
|Stridor, hoarseness, dyspnea||Compression of the trachea|
|Dysphagia, globus sensation||Compression of the larynx and/or trachea|
|Inflow congestion||Compression of the neck veins|
Specific symptoms of goiter
Clear indications of the possible presence of goiter have diffuse or nodular changes of the thyroid tissue.
Diagnosis of Goiter
First signs of goiter
Avoiding necklaces, turtlenecks or an increase in the collar size can be regarded as the first indication of a goiter.
Anamnestically important questions in suspected goiter
A detailed medical history may provide the first evidence for the presence of a goiter. What should be questioned in detail:
- Duration and progression of thyroid enlargement
- Possible exposure of the head and neck region
- Recently occurred hoarseness
- Hormonal changes (puberty, pregnancy, menopause)
- Taking medications
- Iodine intake
- Family history
You should start with an examination. At the beginning of a first-glance examination, you may work with the goiter-size stages classification provided by WHO (see above). You should examine the thyroid with a straight back and a bowed head. You should pay attention to a possible visible enlargement, to nodes and signs of upper inflow congestion.
Palpation stands in the foreground. During the physical examination, it allows making further judgment as regards to the extension of a goiter and other clinical signs of malignancy. What is important in this case:
- Mobility of the tissue
- Any enlargement of the tissue
- Uniform consistency of the tissue
- Possibly to palpate lumps and nodes
- Buzz under the palpating fingers
- Increased sensitivity to touch
- Lymph node enlargement
In addition to palpation, you may also use auscultation. If there is an increased blood supply to the thyroid tissue, this can be perceived as an audible buzz auscultation. If it happens, you should think of the presence of hyperthyroidism.
Further diagnosis in the presence of goiter
With a hardened anamnestic history and physical examination of the suspected goiter, the following examinations should take place:
- Ultrasonography of the thyroid for accurate detection of thyroid enlargement and morphological differentiation of the various forms of goiter
- Determination of TSH, TRH, T3 and T4 for the evaluation of thyroid function
With a multinodular or nodular goiter, the following questions are to be answered: If a thyroid autonomy is available? Is it benign changes or a thyroid malignant tumor if the tissues change? In order to get a differentiated answer to these questions, the following further diagnostic agents should be considered:
- Laboratory diagnostics
- Unenhanced computed tomography
- Magnetic Resonance Imaging
- Fine-needle biopsy
Differential Diagnosis of Goiter
Various forms of goiter
The diagnosis of goiter initially leads to the differentiation in diffuse and nodular goiter. However, among them we may subsume more different goiter forms with their conceptual assignment essentially depending on the nature of the change or the precise location of the thyroid tissue.
|Euthyroid goiter (bland goiter)||Benign, with euthyroid serum levels and normal thyroid function||With normal serum levels without direct clinical significance|
|Euthyroid nodular goiter/ multinodular goiter||Nodular goiter, at the beginning mostly euthyroid, in the further course, there are signs of hyperthyroidism||Hyperthyroidism|
|Diffuse goiter (struma parenchymatosa||Not definable enlargement of the thyroid gland with uniform growth; common cause: iodine deficiency||Puberty goiter, Graves’ disease|
|Basedow’s goiter||Diffuse parenchymal goiter with abundant vascular development, liquid colloid and epithelium tumor||Graves’ disease|
|Lymphatic goiter Hashimoto (struma lymphomatosa Hashimoto)||Over the years, increasing focal or diffuse lymphocytic or plasma cellular infiltration of the thyroid, formation of lymphocytic follicles; final stage: fibrosis and disappearance of goiter parenchyma||Hashimoto’s thyroiditis|
|Neonatal goiter||Thyroid enlargement in the newborn, endemic in iodine-deficient areas||Goiter in the new-born|
Differential diagnosis of thyroid enlargement
Main cause for the diffuse goiter is an alimentary iodine deficiency situation in industrialized countries. Consequence of this is a TSH-independent adaptive response in the sense of hyperplasia. If there is an enlarged thyroid, you have to think about a differential diagnosis:
- Diffuse goiter parenchymatosa
- Diffuse or colloid goiter
- Hypertrophic Hashimoto’s thyroiditis
- Graves’ hyperthyroidism
- De Quervain’s thyroiditis
- Invasive sclerosing thyroiditis (“Riedel’s thyroiditis”)
Differential diagnosis of euthyroid nodular goiter
After noting a euthyroid nodular goiter (nodular goiter), possible malignant and inflammatory changes as well as functional autonomies have to be excluded. It should be included in the differential diagnosis in any case:
- Graves’ hyperthyroidism
- Functional autonomy (focal or disseminated)
- Malignant tissue changes (thyroid cancer)
- Hashimoto’s thyroiditis
Laboratory diagnosis of nodular and multinodular goiter
For the avoidance of medullary thyroid carcinoma (MTC) the determination of thyroid autoantibodies is recommended with a sonographic examination. These are:
- Thyroid peroxidase antibodies (TPO antibodies)
- TSH receptor antibodies (TRAB)
Other laboratory parameters to check the thyroid function are:
- Triiodothyronine (T3)
- Thyroxine (T4)
- Thyroid-stimulating hormone (TSH)
- Thyroid releasing hormone test (TRH test)
- Microscopic antibodies (MAbs)
- Thyroglobulin antibodies (TgAb)
Differential diagnosis of multinodular goiter
A particular challenge in the differential diagnosis of thyroid disease is a multinodular goiter. By means of sonography and scintigraphy, you should be able to identify suspicious focal or disseminated autonomies (a cold/hot node) and make further analysis. The aim of the examination is the detection or exclusion of thyroid autonomy.
If scintigraphically conspicuous nodes are detected, these require a further clarification. This in turn should take place by means of fine-needle biopsy. The main purpose of the fine needle biopsy in this case is the selection of thyroid nodules for the earliest possible histological evaluation of clinically normal or malignant tumors (thyroid carcinoma).
Differential Diagnosis of Throat Swelling
Not every throat swelling is to be regarded automatically as a goiter. So, throat swelling can also occur as part of an increase in the volume of parathyroid glands, salivary glands, lymph nodes and the skin, the blood vessels, the muscles and the skeletal system. The differential diagnosis takes the following specific causes into consideration:
|Lymphadenopathy due to infections, sarcoidosis, lymphadenitis etc.||Very often|
|Salivary gland swelling (tumor/stone/inflammation)||Less common|
|Thrombosis or tumor-related superior vena cava syndrome||Rarely|
Therapy of Goiter
Treatment of individual goiter forms
Initially the motto “wait and watch” should be applied with asymptomatic patients. Treatment is required only in case of complaints, a proven thyroid autonomy or well-secured malignancy.
If waiting is however contraindicated, there is a possibility of drug treatment (levothyroxine, iodide). In addition, a radioiodine therapy or surgical therapy may be considered.
However, each therapeutic procedure should be reviewed in terms of its sensibility prior to the start of the action. So, the majority of patients with a node first require no treatment, whereas, the treatment with malignancy is unquestionable. The thyroid surgery is obligatory for malignancy!
In the case of euthyroid diffuse goiter iodine deficiency is the main cause. Thus, the goal of any treatment should be the correction of intrathyroidal iodine deficiency.
In the case of retrosternal or mediastinal goiter expansion with the impairment of adjacent organs of the respiratory and digestive tract, a thyroidectomy in the affected region should be considered.
Important to Remember
- Goiter is a symptom, not a disease.
- Initially it indicates the enlargement of the thyroid.
- Rough classification of goiter: Diffuse and nodular goiter types
In case of a goiter to be suspected of, you should always exclude a possibly present malignancy.
Evidences of a goiter include:
- Thyroid enlargement
- Nodules under the palpating fingers
- Difficulty swallowing, etc.
The examination of the eventually degenerated thyroid tissues occurs via sonography, scintigraphy and fine needle biopsy.
In addition to the goiter, further possible changes of the neck should be taken into consideration with the present throat swelling as they may indicate entirely different diseases, such as swollen lymph nodes, or the increase in the volume of salivary glands.
The answers are below the references.
1. A lack of iodine cannot result in:
- Lowering of thyroid stimulating hormone (TSH) plasma concentration
- Reduction of triiodothyronine plasma concentration
- Thyroid enlargement (goiter)
- Growth failure
- Disturbances of intellectual development
2. Triiodothyronine (T3) and thyroxine (T4) hormones are formed in the thyroid. The precursor of these hormones is deposited extracellularly in the follicles from which the finished thyroid hormones are released by intracellular proteolysis. What is located in the follicles of the thyroid gland?
- Thyrotropin-releasing hormone (TRH)
- Thyroxine-binding globulin
3. Disorders of synthesis of thyroid hormones and regulation of the thyroid function are associated with a variety of symptoms in children and adults. Hyperthyroidism can be caused by autoantibodies that are bound to receptors with the thyroid epithelial cells. Which receptors are activated by these autoantibodies?
- Thyroid-stimulating hormone (TSH)
- Thyroliberin (TRH)