Toxic multinodular goitre
| Toxic multinodular goiter | |
|---|---|
| Classification and external resources | |
| ICD-10 | E05.2 |
| ICD-9 | 242.3 |
| DiseasesDB | 13184 |
| MedlinePlus | 000317 |
| eMedicine | med/920 |
Toxic multinodular goiter (also known as toxic nodular goiter, toxic nodular struma) is a common cause of hyperthyroidism[1][2] in which there is excess production of thyroid hormones from functionally autonomous thyroid nodules, which do not require stimulation from thyroid stimulating hormone (TSH).[3]
It is the second most common cause of hyperthyroidism (after Graves' disease) in the developed world. In countries where the population is iodine-deficient i.e. the developing world, iodine deficiency is the most common cause of hypothyroidism. (Decreased iodine leads to decreased thyroid hormone.) However, iodine deficiency can cause goitre (thyroid enlargement); within a goitre, nodules can develop. Risk factors for toxic multinodular goiter include individuals over 60 years of age and being female.[4]
Symptoms
Symptoms of toxic multinodular goitre are similar to that of hyperthyroidism, including:[4]
- heat intolerance
- muscle weakness/wasting
- hyperkinesis
- 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)
Causes
Sequence of events:[5]
- Iodine deficiency leading to decreased T4 production.
- 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 hyperthryoidism.
Treatments
Toxic multinodular goiter can be treated with antithyroid medications such as propylthiouracil or methimazole, radioactive iodine, or with surgery.[4] Another treatment option in recent years (2013) is ethanol ablation of the nodules.
Related eponym
Plummer's disease is named after the American physician Henry Stanley Plummer but refers to a single toxic nodule (adenoma) which may present with the background of a suppressed multinodular goitre.[6]
References
- ↑ de Rooij, A; Vandenbroucke, JP; Smit, JW; Stokkel, MP; Dekkers, OM (2009). Clinical outcomes after estimated versus calculated activity of radioiodine for the treatment of hyperthyroidism: systematic review and meta-analysis.journal=European journal of endocrinology 161 (5). pp. 771–777. doi:10.1530/EJE-09-0286. PMID 19671708.
- ↑ Krohn, K; Fuhrer, D; Bayer, Y; Eszlinger, M; Brauer, V; Neumann, S; Paschke, R (2005). "Molecular pathogenesis of euthyroid and toxic multinodular goiter.". Endocrine reviews 26 (4): 504–524. doi:10.1210/er.2004-0005. PMID 15615818.
- ↑ Reid, JR; Wheeler, SF (2005). "Hyperthyroidism: diagnosis and treatment.". American family physician 72 (4): 623–630. PMID 16127951.
- ↑ 4.0 4.1 4.2 A.D.A.M. Medical Encyclopedia (2012). "Toxic nodular goiter". U.S. National Library of Medicine. Retrieved 30 January 2013.
- ↑ http://emedicine.medscape.com/article/120497-overview
- ↑ Plummer's disease eponymously named after Henry Stanley Plummer at Who Named It?