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enlargement of the thyroid gland, causing a swelling in the front part of the neck; called also struma. adj., adj goit´rous. If there is evidence of pressure against the throat, or the possibility of a malignancy, the goiter may be removed surgically. Simple endemic goiter is usually caused by lack of iodine in the diet. In graves' disease, goiter is accompanied by excessive thyroid hormones in the blood and symptoms of hyperthyroidism.
aberrant goiter goiter of a supernumerary thyroid gland.
adenomatous goiter that caused by adenoma or multiple colloid nodules of the thyroid gland.
Basedow goiter a colloid goiter that has become hyperfunctioning after administration of iodine.
colloid goiter one that is large and soft and has distended spaces filled with colloid.
cystic goiter one with cysts formed by mucoid or colloid degeneration.
diffuse toxic goiter exophthalmic goiter.
endemic goiter goiter occurring widely in a geographic region where the food or water is deficient in iodine. Treatment consists of iodine replacement; although this will not cure the condition, it can stop it from enlarging, and iodine administered in advance will prevent development of goiter.
exophthalmic goiter any type accompanied by exophthalmos.
fibrous goiter goiter in which the thyroid capsule and stroma are hyperplastic.
follicular goiter parenchymatous goiter.
intrathoracic goiter one with part of the enlarged gland in the thoracic cavity.
iodide goiter that occurring in reaction to iodides at high concentrations, due to inhibition of iodide organification.
multinodular goiter one with circumscribed nodules within the gland.
nontoxic goiter that occurring sporadically and not associated with hyperthyroidism or hypothyroidism.
parenchymatous goiter one with increase in follicles and proliferation of epithelium.
perivascular goiter one that surrounds a large blood vessel.
retrovascular goiter one with processes behind a large blood vessel.
substernal goiter one whose lower part lies beneath the sternum.
suffocative goiter one that causes dyspnea due to pressure.
toxic multinodular goiter hyperthyroidism arising in a multinodular goiter, usually of long standing.
vascular goiter one due chiefly to dilatation of the blood vessels of the thyroid gland.
a form of goiter in which the contents of the follicles increase greatly, causing pressure atrophy of the epithelium so that the gelatinous matter predominates in the tumor.
Synonym(s): struma colloides
colloid goiterEndemic goiter, see there.
col·loid goi·ter(kol'oyd goy'tĕr)
A form of goiter in which the contents of the follicles increase greatly, causing pressure atrophy of the epithelium so that the gelatinous matter predominates in the tumor.
enlargement of the thyroid gland, causing a swelling in the front part of the neck.
multilobular goiters cause thyroid enlargement in cats.
is characterized by the presence of a large soft thyroid gland with its glandular space distended with colloid. Most cases occur in neonatal lambs, calves and kids which show a high rate of stillbirths and weakness and a high mortality rate. Enlarged thyroid glands and alopecia are good indicants of the existence of a nutritional deficiency of iodine, the usual cause of goiter in animals.
an impairment in thyroglobulin synthesis is thought to be the cause of inherited, congenital goiter recorded in sheep, cattle and goats. The thyroid gland is enlarged, there is a high neonatal mortality, a silky wool in sheep and a rough, sparse haircoat in goats. Called also inherited goiter.
there are a number of goitrogens in the environment of grazing animals. Their effect is almost entirely on the newborn. Common agents are low level intakes of cyanogenetic glycosides, e.g. in white clover, the glucosinolates in Brassica spp. plants, and mimosine in Leucaena leucocephala.
diffuse hyperplasia is the standard response to dietary iodine deficiency and to poisoning by plant goitrogens. It may also be caused by persistent exposure of the fetus to a high iodine intake of the dam. See also iodide goiter (below). Neonates are the usual subjects and the disease is manifested by clinical goiter, often sufficient to cause dystocia, and weak neonates with a high rate of stillbirths and deaths soon after birth.
see dyshormonogenetic goiter (above).
that occurring in reaction to iodides at high concentrations, due to inhibition of iodide organification.
an endocrinologically inactive nodular enlargement of the thyroids in old dogs and horses. In old cats similar goiters sometimes develop functional adenomas.