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Autoimmune polyglandular syndrome type 1 (NORD)
Adrenal insufficiency: Pathology review
Adrenal masses: Pathology review
Cushing syndrome and Cushing disease: Pathology review
Diabetes insipidus and SIADH: Pathology review
Diabetes mellitus: Pathology review
Hyperthyroidism: Pathology review
Hypopituitarism: Pathology review
Hypothyroidism: Pathology review
Multiple endocrine neoplasia: Pathology review
Neuroendocrine tumors of the gastrointestinal system: Pathology review
Parathyroid disorders and calcium imbalance: Pathology review
Pituitary tumors: Pathology review
Thyroid nodules and thyroid cancer: Pathology review
Toxic multinodular goiter
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in toxic multinodular goiter p. 348
So toxic multinodular goiter is a condition where the thyroid gland enlarges and is filled with lots of little nodules of tissue - each of which produce so much thyroid hormone that it becomes harmful to the body.
Normally, the hypothalamus, which is located at the base of the brain, detects low blood levels of thyroid hormones and releases thyrotropin-releasing hormone into the hypophyseal portal system - which is a network of capillaries linking the hypothalamus to the anterior pituitary.
The anterior pituitary then releases thyroid-stimulating hormone, also called thyrotropin or simply TSH.
TSH stimulates the thyroid gland which is a gland located in the neck that looks like two thumbs hooked together in the shape of a “V”.
The thyroid gland is made up of thousands of follicles, which are small spheres lined with follicular cells.
Follicular cells convert thyroglobulin, a protein found in follicles, into two iodine-containing hormones, triiodothyronine or T3, and thyroxine or T4.
Once released from the thyroid gland, these hormones enter the blood and bind to circulating plasma proteins.
Only a small amount of T3 and T4 will travel unbound in the blood, and these two hormones get picked up by nearly every cell in the body.
Once inside the cell T4 is mostly converted into T3, and it can exert its effect. T3 speeds up the basal metabolic rate.
Toxic multinodular goiter (TMNG) is a condition characterized by the growth of multiple nodules in the thyroid gland, which can cause the gland to become enlarged and produce too much thyroid hormone. The excess thyroid hormone production can lead to symptoms of hyperthyroidism, including weight loss, rapid heart rate, tremors, and heat intolerance.
TMNG typically develops after prolonged iodine deficiency, which causes hypertrophy and hyperplasia of the thyroid gland. Continued follicular cell division can lead to a genetic mutation of the TSH receptor turning a non-toxic multinodular goiter into a toxic multinodular goiter.
Symptoms include an enlarged thyroid as well as the typical symptoms of hyperthyroidism like weight loss, a rapid heart rate, and hyperactivity. The treatment for TMNG involves medications like beta-blockers and radioactive iodine, or surgery to remove part or all of the thyroid gland.
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