Toxic multinodular goitre
Encyclopedia
Toxic multinodular goitre (also known as toxic nodular goitre, toxic nodular struma) is a form of hyperthyroidism
Hyperthyroidism
Hyperthyroidism is the term for overactive tissue within the thyroid gland causing an overproduction of thyroid hormones . Hyperthyroidism is thus a cause of thyrotoxicosis, the clinical condition of increased thyroid hormones in the blood. Hyperthyroidism and thyrotoxicosis are not synonymous...

 - where there is excess production of thyroid hormones. It is characterized by functionally autonomous nodules. It emerges insidiously from nontoxic multinodular goitre.

It is the second most common cause of hyperthyroidism
Hyperthyroidism
Hyperthyroidism is the term for overactive tissue within the thyroid gland causing an overproduction of thyroid hormones . Hyperthyroidism is thus a cause of thyrotoxicosis, the clinical condition of increased thyroid hormones in the blood. Hyperthyroidism and thyrotoxicosis are not synonymous...

 (after Graves' disease
Graves' disease
Graves' disease is an autoimmune disease where the thyroid is overactive, producing an excessive amount of thyroid hormones...

) 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.

Symptoms

Symptoms of toxic multinodular goitre are similar to that of hyperthyroidism
Hyperthyroidism
Hyperthyroidism is the term for overactive tissue within the thyroid gland causing an overproduction of thyroid hormones . Hyperthyroidism is thus a cause of thyrotoxicosis, the clinical condition of increased thyroid hormones in the blood. Hyperthyroidism and thyrotoxicosis are not synonymous...

, including:
  • heat intolerance
  • muscle weakness/wasting
  • hyperkinesis
    Hyperkinesis
    Hyperkinesia, also known as hyperkinesis, refers to an increase in muscular activity that can result in excessive abnormal movements, excessive normal movements, or a combination of both...

  • tremor
    Tremor
    A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving to-and-fro movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the...

  • irritability
  • weight loss
    Weight loss
    Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...

  • osteoporosis
    Osteoporosis
    Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...

  • increased appetite
  • goitre
    Goitre
    A goitre or goiter , is a swelling in the thyroid gland, which can lead to a swelling of the neck or larynx...

     (swelling of the thyroid gland)
  • tachycardia
    Tachycardia
    Tachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...

     (high heart rate - above 100 bpm at rest in adults)

Causes

Sequence of events
  1. Iodine deficiency leading to decreased T4 production.
  2. Induction of thyroid cell hyperplasia due to low levels of T4. This accounts for the multinodular goitre appearance.
  3. Increased replication predisposes to a risk of mutation in the TSH receptor.
  4. If the mutated TSH receptor is constitutively active, it would then become 'toxic' and produces excess T3/T4 leading to hyperthryoidism.

Related eponym

Plummer's disease is named after the American physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...

 Henry Stanley Plummer
Henry Stanley Plummer
Henry Stanley Plummer, M.D. was a prominent internist and endocrinologist who, along with Drs. William Mayo, Charles Mayo, Stinchfield, E. Starr Judd, Christopher Graham, and Donald Balfour founded Mayo Clinic. Dr...

but refers to a single toxic nodule (adenoma) which may present with the background of a suppressed multinodular goitre.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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