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59 Cards in this Set
- Front
- Back
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Where will a thyroglossal duct cyst most commonly be found?
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Midline neck above the thyroid isthmus but below the hyoid bone
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What can potentially develop from a thyroglossal duct cyst if it contains thyroid tissue?
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Primary thyroid carcinoma
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What are the 3 most common causes of hyperthyroidism?
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1. Graves disease
2. Hyperfunctional multinodular goiter 3. Hyperfunctional thyroid adenoma |
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What are the top 3 causes of Hyperthyroidism?
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1. Graves disease
2. Hyperfunctional Multinodular Goiter 3. Hyperfunctional Thyroid Adenoma |
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What are 4 less common causes of Hyperthyroidism?
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-TSH secreting pituitary adenoma
-Thyroiditis -Struma ovarii -Factitious thyrotoxicosis |
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What changes physiologicaly in hyperthyroidism?
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Basal metabolic rate is generally increased
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What is the best lab test for hyperthyroidism?
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TSH
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What will the TSH/T4 be in hyperthyroid usually?
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Low TSH
High T4 |
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When would both the TSH/T4 be elevated in hyperthyroidism?
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If the cause is a TSH-secreting pituitary adenoma
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What is a useful lab test for diagnosing hyperthyroidism in addition to measuring TSH/T4?
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Radioactive Iodine uptake
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What pattern of RAI uptake will be seen in
-Graves disease -Toxic adenoma -Thyroiditis |
Graves: diffusely increased uptake
Toxic adenoma: Increased uptake in just one nodule Thyroiditis: decreased uptake |
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What are 4 causes of Primary hypothyroidism?
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-Surgery/Radiation ablation
-Autoimmune disease -Inborn errors of thyroid metabolism -Drugs |
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What is the autoimmune disease of primary hypothyroidism?
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Hashimoto's
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What is 2ndary hypothyroidism?
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Decreased thyroid function due to pituitary failure
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What causes tertiary hypothyroidism?
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Hypothalamic failure
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What is Cretinism?
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Hypothyroidism in infants and young children
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What is Cretinism usually caused by?
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Dietary deficiency of iodine
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What are 4 symptoms of Cretinism?
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-Mental retardation
-Short stature -Tongue protrusion -Coarse facial features |
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What is myxedema?
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The constellation of findings in Hypothyroidism seen in older children and adults
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What will the lab findings for TSH and T4 be in primary hypothyroidism?
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T4 will be low
TSH will be high |
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What will the lab findings for TSH and T4 be in secondary or tertiary hypothyroidism?
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TSH will be low
T4 will be low |
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What is Thyroiditis?
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Inflammation of the thyroid gland
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What is Hashimoto's Thyroiditis?
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Inflammation of the thyroid gland leading to failure
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What causes the gradual failure of the thyroid in Hashimoto's?
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Autoimmune destruction
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What clinical symptom is commonly seen in Hashimoto's thyroiditis?
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Goiter
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What is the avg age group and sex ratio seen with Hashimoto's thyroiditis?
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45-65 yrs old
F: M = 10-20:1 |
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How does the pathology of Hashimoto's start and progress?
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CD4+ Thelper cells become sensitized to self antigens and initiate destruction of the thyroid
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What are 3 cells that are stimulated by the CD4+ Th cells sensitized to self thyroid antigens?
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1. CTLs
2. Th1 cells 3. Plasma cells |
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What results from the CTL stimulation?
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Fas/FasL interaction and cell-mediated cytotoxicity
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What results from the Th1 differentiation?
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Secretion of IFN-y and activation of macrophages for thyrocyte injury
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What results from the Plasma cell stimulation?
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Secretion of anti-thyroid antibodies for NK-cell mediated ADCC
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Are the thyroid hormones always decreased in Hashimoto's?
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No, initially they mey be elevated to inappropriate release due to the inflammatory destruction of the gland.
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Do all cases of Hashimoto's end in hypothyroidism eventually?
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Yes
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Is the thyroid enlargement in Hashimoto's painful or painless?
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Painless
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What does Hashimotos thyroiditis increase the risk for patients developing? (6 diseases)
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-Type I diabetes
-Autoimmune adrenalitis -SLE, myasthenia gravis, SS -Bcell NHL |
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What are 2 other types of thyroiditis that cause HYPERthyroid function?
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-Subacute Granulomatous Thyroiditis
-Subacute Lymphocytic Thyroiditis |
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What are the main things to remember about Subacute Granulomatous Thyroiditis?
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-Younger adults (30-50 yo)
-Postviral Upper resp infection -Neck PAIN -Self limited/complete recovery |
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Despite the increased thyroid function, what will the RAI uptake be in SGT?
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Decreased
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In what patients is Subacute Lymphocytic thyroiditis most commonly seen?
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Postpartum women
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What are the 3 main things to remember about SLT?
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-Post partum women
-NOT painful -Self-limited, may be asympmt |
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What is Fibrous Thyroiditis often confused as? Why?
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Carcinoma - because of extensive fibrosis that creates a hard and fixed thyroid mass.
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What is the most common cause of endogenous hyperthyroidism?
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GRAVES disease
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What is the triad of clinical findings seen in Graves disease?
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1. Diffuse enlargement of the thyroid causing Hyperthyroidism
2. Opthalmopathy 3. Infiltrative dermopathy |
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What is the infiltrative dermopathy in Graves also called?
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Pretibial myxedema
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In what age /sex of patients is Graves most often seen?
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Age: 20-40
Sex: Females 7: Males 1 |
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What causes the thyroid hyperfunction in Graves?
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Autoantibodies to the TSH receptor that stimulate it
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What are the autoantibodies in Graves disease called?
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TSI - Thyroid stimulating globulin
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What type of immunoglobulin is the TSI?
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IgG
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At what other tissue site is the TSH receptor also expressed and thus stimulated by the TSI in graves?
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Orbital preadipocyte fibroblasts
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What is the effect that TSI stimulation of the TSH receptor on Orbital preadipocyte fibroblasts has?
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Exopthalmosis
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What happens to the exopthalmosis in Graves disease when treated?
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It may go away, or may persist
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How is Graves disease diagnosed?
-Lab findings -RAI uptake |
Lab: increased T3/T4, low TSH
RAI: diffusely increased |
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What is a Goiter in general?
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An enlargement of the thyroid gland from any benign cause
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What is the most common cause of Goiters?
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Dietary deficiency of iodine resulting in decreased circulating T3/T4, so upregulated TSH
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What are the thyroid functionality most often in patients with goiters?
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Euthyroid
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What are the T3/T4/TSH levels usually in patients w/ goiters?
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T3/T4 = normal
TSH = normal to sl high |
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What type of goiter is seen in
-Young adults -Older adults |
Young: simple
Older: multinodular |
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What is a complication that Nodular goiters can lead to?
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Secondary hyperthyroidism due to toxic multinodular goiter
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In what syndrome is Toxic multinodular goiter a component?
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Plummer syndrome
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