Thyroid Flashcards by Tanner KG

essential action of the thyroid

increase basal metabolic rate

How well did you know this?

Not at all

Perfectly

TSH stimulates the production of…

Thyroglobulin (TG)

*iodide is incorporated with TG before being cleaved into T3 and T4

How well did you know this?

Not at all

Perfectly

causes of primary hyperthyroidism

*most common*
diffuse hyperplasia (Graves)
hyperfunctioning multinodular goiter 
hyperfunctioning thyroid adenoma

How well did you know this?

Not at all

Perfectly

cause of secondary hyperthyroidism

pituitary adenoma

How well did you know this?

Not at all

Perfectly

primary vs secondary hyperthyroidism

elevated T3/T4 + low TSH = primary

elevated T3/T4 + high TSH = secondary

How well did you know this?

Not at all

Perfectly

clinical presentation of apathetic hyperthyroidism

older adults with masked symptomatology

unexplained weight loss
CV disease

How well did you know this?

Not at all

Perfectly

clinical presentation of classic hyperthyroidism

perspiration
facial flushing
restlessness
exophthalmos
palpitations/tachy
diarrhea
weight loss
heat intolerance

How well did you know this?

Not at all

Perfectly

thyroid storm

hyperthyroid crisis:
fever
tachy
CHF
diarrhea
jaundice

How well did you know this?

Not at all

Perfectly

thyroid storm causes

pregnancy/postpartum
hemithyroidectomy
drugs (amiodarone)

How well did you know this?

Not at all

Perfectly

thyroid storm tx

treat manifestations:
beta blockers

treat underlying disease:
high dose iodide
thionamide
radioiodine ablation
surgery

How well did you know this?

Not at all

Perfectly

most common etiology of hyperthyroidism

graves disease

How well did you know this?

Not at all

Perfectly

classic diagnostic triad of graves disease

autoimmune hyperthyroidism with gland enlargement
infiltrative ophthalmology
pretibial myxedema

How well did you know this?

Not at all

Perfectly

pathogenesis of graves disease affecting the orbit

lymphocytes invade preorbital space
fibroblasts have TSH receptor
EOM swelling
matrix accumulates
adipocytes expand

How well did you know this?

Not at all

Perfectly

Graves lab results

high T3/T4
low TSH
high TSI (thyroid stimulating Ig)

How well did you know this?

Not at all

Perfectly

causes of primary hypothyroidism

Hashimoto thyroiditis
granulomatous thyroiditis
subacute lymphocytic thyroiditis
reidel thyroiditis

How well did you know this?

Not at all

Perfectly

causes of secondary hypothyroidism

pituitary failure

hypothalamic failure

How well did you know this?

Not at all

Perfectly

presentation of congenital hypothyroidism/cretinism

mental retardation
growth retardation
coarse facial features
umbilical hernias

How well did you know this?

Not at all

Perfectly

etiology of congenital hypothyroidism

iodine deficiency of mother in pregnancy (endemic)
or
genetic alterations in thyroid metabolic pathways

How well did you know this?

Not at all

Perfectly

clinical presentation of hypothyroidism/myxedema

mental/physical sluggishness
weight gain
cold intolerance
low cardiac output
hypercholesterolemia
dry, brittle hair and nails
diastolic HTN
follicular keratosis

How well did you know this?

Not at all

Perfectly

hashimoto thyroiditis

autoimmune hypothyroidism: auto-Ab against thyroglobulin and thyroid peroxidase

most common cause of hypothyroidism in iodide-sufficient areas

progression of Hashimoto

immune-mediated insult
hyperactivity and enlargement
follicular cell exhaustion

clinical presentation of hashimoto

hypothyroid sx

exception: hashitoxicosis (early disease)

histo of hashimoto

lymphocytic infiltrate with germinal centers

Hurthle cell metaplasia: atrophic follicle cells with eosinophilic change

hashimoto Abs

hTg-Ab

hTPO-Ab

graves Abs

primarily TSHR-Ab (TSI) but hTg-Ab and hTPO-Ab can also be present

subacute lymphocytic thyroiditis

autoimmune!! transient period of thyroid hormone irregularities that presents as hypo- or hyper-thyroid with goiter can progress to permanent hypothyroidism ex: postpartum thyroiditis

granulomatous thyroiditis

aka de Quervains *painful* granulomatous response to viral infection hypo- or hyperthyroid

Riedel thyroiditis

fibrosing thyroid process that extends into adjacent tissue presents as euthyroid *IgG4-related disease

histo of Riedel thyroiditis

fibrosis lymphocytes plasma cells

subacute lymphocytic Abs

TPO Abs

goiter

thyroid enlargement diffuse vs nodular nontoxic vs toxic benign vs malignant

diffuse nontoxic goiter

endemic --> goiter due to iodine deficiency goitrogens sporadic

presentation of diffuse nontoxic goiter

*euthyroid* ``` sx due to mass effect: dysphagia hoarseness stridor SVC syndrome ```

multinodular goiters

occur due to hyperplasia and regression cycle may have neoplastic nature produce mass effect

which nodules are more likely to be benign: hot or cold

hot --> tx with excision or ablation

benign thyroid nodules

hyperplastic/adenomatoid nodules | follicular adenoma

malignant thyroid nodules

papillary thyroid CA follicular/Hurthle cell CA anaplastic CA medullary CA

most common malignant thyroid tumor

papillary thyroid carcinoma

papillary thyroid CA mutations

RET-PTC | BRAF

histo of papillary thyroid CA

papillary architecture psammoma bodies "orphan annie eye nuclei"

papillary CA variants

follicular variant tall cell variant diffuse sclerosing

papillary CA follicular variant

follicular architecture but nuclear features of papillary RAS mutation

papillary CA tall cell variant

older patients aggressive! histo looks like columnar cells

papillary CA diffuse sclerosing variant

kids and young adults | risk of metastasis but good prognosis overall

follicular CA

more common in areas with iodide deficiency RAS mutation **PAX8/PPARG mutations**

invasion properties of follicular CA

invasion of the capsule (mushroom) | angioinvasion (hematogenous mets)

anaplastic CA

very uncommon occurs in elderly patients highly aggressive and presents with mass effect TP53 mutation

thyroid C cells

responsible for calcitonin secretion

medullary carcinoma

neuroendocrine tumor derived from C cells: blue cells with dispersed chromatin amyloid C-cell hyperplasia RET mutation