Toxic multinodular goitre
Toxic multinodular goiter | |
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Other names | Toxic nodular goiter, Plummer's disease, multinodular toxic goiter, TMNG, MNTG |
Most common causes of hyperthyroidism by age.[1] | |
Specialty | Endocrinology |
Toxic multinodular goiter (TMNG), also known as multinodular toxic goiter (MNTG), is an active
It is a common cause of hyperthyroidism
Toxic multinodular goiter is the second most common cause of hyperthyroidism (after Graves' disease) in the developed world, whereas iodine deficiency is the most common cause of hypothyroidism in developing-world countries where the population is iodine-deficient. (Decreased iodine leads to decreased thyroid hormone.) However, iodine deficiency can cause goiter (thyroid enlargement); within a goitre, nodules can develop. Risk factors for toxic multinodular goiter include individuals over 60 years of age and being female.[5]
Signs and symptoms
Symptoms of toxic multinodular goitre are similar to that of hyperthyroidism, including:[5]
- heat intolerance
- muscle weakness/wasting
- hyperactivity
- fatigue
- tremor
- irritability
- weight loss
- osteoporosis
- increased appetite
- non-painful goitre (swelling of the thyroid gland)
- tachycardia (high heart rate - above 100 beats per minute at rest in adults)
- tracheal compression
- exophthalmos
Causes
Sequence of events:[6]
- Iodine deficiency leading to decreased T4production.
- Induction of thyroid cell hyperplasia due to low levels of T4. This accounts for the multinodular goitre appearance.
- Increased replication predisposes to a risk of mutation in the TSH receptor.
- If the mutated TSH receptor is constitutively active, it would then become 'toxic' and produces excess T3/T4 leading to hyperthyroidism.
Diagnosis
Hyperthyroidism is diagnosed by evaluating symptoms and physical exam findings, and by conducting laboratory tests to confirm the presence of excess thyroid hormones. It is characterized by high levels of thyroid hormone in the blood along with a low level of thyroid-stimulating hormone (TSH). After diagnosing hyperthyroidism, a
Fine-needle aspiration for
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Diffuse thyroid hyperplasia typically shows variably sized follicles
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Thyroid hyperplasia with a hyperplastic nodule. It characteristically has no capsule (distinguishing it from thyroid adenoma or carcinoma).
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The follicular linings may be thickened, with papillary projections (but lack nuclear features ofpapillary thyroid carcinoma)
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The epithelium may also be flattened by enlarged follicles.
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It can show hypercellular or microfollicular areas. There is no surrounding capsule (in contrast, acarcinomais generally encapsulated).
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As shown in these microfollicles, it can have mildly enlarged nuclei with mildly clumped chromatin, and clear cytoplasms, but cellular characteristics of papillary thyroid carcinoma are absent.
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Thyroid hyperplasia with a Sanderson polster, which is a group of small follicles that protrude into the lumen of a larger follicle. It should not be confused for papillary projections.
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Various forms of degeneration are typically seen, with various forms pictured.
Treatments
Toxic multinodular goiter can be treated with antithyroid medications such as
A Cochrane review compared treatments using recombinant human thyrotropin-aided radioactive iodine to radioactive iodine alone.[10] In this review it was found that the recombinant human thyrotropin-aided radioactive iodine appeared to lead to a greater of thyroid volume at the increased risk of hypothyroidism.[10] No conclusive data on changes in quality of life with either treatments were found.[10]
History
The
References
- PMID 21357288.
- PMID 19671708.
- PMID 15615818.
- PMID 16127951.
- ^ a b c A.D.A.M. Medical Encyclopedia (2012). "Toxic nodular goiter". U.S. National Library of Medicine. Retrieved 30 January 2013.
- ^ Toxic Nodular Goiter at eMedicine
- ^ "Toxic Nodule and Toxic Multinodular Goiter". American Thyroid Association. Retrieved 2023-02-15.
- ^ Philip R Orlander, MD, FACP; Chief Editor: George T Griffing, MD. "Toxic Nodular Goiter Workup". Medscape.
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has generic name (help)CS1 maint: multiple names: authors list (link) Updated: Oct 25, 2021 - ISBN 9781416055839.
- ^ PMID 34961921.
- ^ Elsevier, Dorland's Illustrated Medical Dictionary, Elsevier.
- Who Named It?