Goiter overview
|
Goiter Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Goiter overview On the Web |
|
American Roentgen Ray Society Images of Goiter overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Historical Perspective
Classification
In 1974, an international committee of thyroid pathologists published the first WHO histological classification of thyroid tumours which had served as a basis for various clinical, pathological, and epidemiological studies.Goiter may also be classified according to various classification methods based on etiological, epidemiological, anatomical, pathological, functional and morphological factors.
Pathophysiology
When the TRH-TSH thyroid hormone axis is interfered, it results in the structural and functional changes of the thyroid gland. Increased TSH production is trigerred by a deficiency in thyroid hormone synthesis or intake. In order to normalize thyroid hormone levels, the increase in TSH leads to increased cellularity and hyperplasia of the thyroid gland and when this process is continuous, it leads to goiter.
Causes
Various factors have been associated with the cause of goiter such as hereditary, hormonal, dietary, pharmacological, physiological, environmental and pathological factors. The most common causes bering, iodine deficiency, grave's disease and hashimoto's disease. Goiter may be caused by a mutation in the genes such as the thyroglobulin (Tg) gene, thyroid-stimulating hormone receptor (TSHR) gene and the Na+/I- symporter (NIS) gene.
Differentiating Goiter from other Diseases
As Goiter manifests in a variety of clinical forms, differentiation must be established in accordance with the particular subtype.
Epidemiology and Demographics
Risk Factors
As Goiter manifests in a variety of clinical forms, differentiation must be established in accordance with the particular subtype.
Screening
Screening for Goiter initially involves physical examination followed by blood tests for free T4 and TSH and finally thyroid scan, ultrasound and biopsy to rule out malignanacy.
Natural History, Complications and Prognosis
Slow growth of the nodules is observed in benign goiter. Quick growth and large size of goiter causing compressive symptoms may be suggestive of thyroid cancer. Common complications of Goiter include those related to the enlarged gland and those related to thyroidectomy. Prognosis is generally good for benign goiters. Although the prognosis is good and the risk is low, caution is advised for the possible development of malignancy. Careful monitoring of size, shape and consistency associated with pain is advised. Radiation exposure has been attributed to the possible development of malignancy.
Diagnosis
History and Symptoms
A history of low iodine intake, history of use of therapeutic drugs that hinder normal thyroid hormonal activity, radiation exposure and positive family history of thyroid diseases. Symptoms of Goiter include, swelling at the base of the neck, difficulty swallowing, hoarseness of voice and difficulty in breathing.
Physical Examination
Physical examination of patients with Goiter is usually remarkable for swelling at the base of the neck.
Laboratory Findings
Patients with Goiter may be in a euthyroid, hypothyroid or hyperthyroid state. Patients should be evaluated for free T4, T3, TSH levels and TPO antibodies.
Electrocardiogram
There are no ECG findings associated with Goiter.
Chest X Ray
Plain x-ray radiography findings of the neck suggestive of Goiter may reveal tracheal deviation or compression and calcification within the goitre.
CT
There are no CT scan findings associated with Goiter.
MRI
There are no MRI findings associated with Goiter.
Echocardiography or Ultrasound
Ultrasound may be helpful in determining the physical characteristics of the Goiter. Ultrasound also aids in ultrasound guided FNAC.
Other Imaging Findings
Thyroid radioisotope scan may be helpful in the diagnosis of Goiter.
Other Diagnostic Studies
Barium swallow may be helpful in assessing compression of the esophagus due to Goiter. Indirect laryngoscopy helps assess the mobility of the vocal cord.
Treatment
Medical Therapy
Pharmacologic medical therapy for Goiter involves normalizing hormone levels and treating the inflammation. Treatment regimen involves Lugol’s iodine, antithyroid drugs and β-adrenergic blockers. In some cases, radioactive iodine may be used to treat an overactive thyroid gland.
Surgery
Thyroid surgery may be advised in cases of goiter depending upon the symptoms and adverse effects associated with the development of goiter such as, compression related symptoms, thyroid hyper-function and thyroid cancer.