Clinical Flashcards
most widely used test to determine whether thyroid dysfunction exists:
TSH measurement
Increased T3 is useful in:
thyrotoxicosis
best method to differentiate benign from malignant and diffuse goiters:
thyroid biopsy – fine needle aspiration
Anti-TPO Abs:
Hashimoto’s thyroiditis
TSI (thyroid stimulating immunoglobulin):
Graves disease
TQ
- symptoms of faintness, facial congestion
- external jugular venous obstruction
- when arms are raised above head, thyroid is drawn into thoracic inlet
Pemberton’s sign
hoarseness may due to compression of:
recurrent laryngeal nerve
think malignancy.
- focal patches of hyperfunctioning follicular cells working independently of TSH due to mutation in TSH receptor
- increased release of T3 and T4
- often elderly, atrial fib
- tremors, weight loss
- hot nodules are rarely malignant
toxic multinodular goiter
TQ
tumors of parathyroid, pancreas, pituitary
think…
MEN 1
TQ
medullary CA of thyroid, pheo, hyperparathyroidism
think…
MEN 2A
TQ
mucosal neuromas, medullary CA of thyroid, pheo, possibly marfanoid habitus
think…
MEN2B
cold nodule on thyroid scan
think…
cancer
psammomatous calcifications
think…
papillary CA
- RET mutations
- produce excessive amounts of calcitonin
- mets to lung, liver, bone
- cold nodule on thyroid scan
- tx: total thyroidectomy with T4 supplementation later
medullary CA
- menstrual irregularities
- weight gain, constipation, fatigue
- goiter
- bradycardia
- HTN
- DTRs “hung up”
hypothyroidism
- autoimmune disorder (anti-TPO, anti-microsomal, anti-thyroglobulin Abs)
- increased risk of non-Hodkin lymphoma
- Hurthle cells, lymphocytic infiltration with germinal centers
- moderately enlarged, nontender thyroid
- reduced SV, increased PVR (why they’re cold), increased BP
Hashimoto’s (autoimmune) thyroiditis
TQ
meds that cause hypothyroidism: (4)
- amiodarone (iodine content»_space; negative feedback to decrease conversion of total T4 to total T3)
- lithium carbonate
- IFNa
- IL-2
greatest complication of hypothyroid (mortality > 50%):
myxedema coma
- older women
- winter season
- hypothermic, hypoventilation
- hypoglycemia
- hyponatremia
- shock/death
- MC cause of hyperthyroidism
- auto-Abs (IgG) stimulate TSH receptors (thyroid stimulating immunoglobulin)
- exophthalmos: proptosis, extraocular muscle swelling
- dermal fibroblasts (pretibial myxedema)
- often presents during stress (e.g., childbirth)
Graves disease
-usually benign follicular adenoma; hot nodule on one side with decreased uptake on other side
Toxic adenoma causing hyperthyroidism
amiodarone may cause thyrotoxicosis
Rx?
Rx: ß-blocker and prednisone
- hyperactive, irritable
- palpitations
- weight loss with increased appetite
- polyuria
- tachycardia, atrial fib* in elderly; angina, CHF
- goiter (firm), tremor
- exophthalmos
- dermopathy (pretibial myxedema)
thyrotoxicosis
-elderly, atrial fib, fatigue, weight loss – mistaken for depression
apathetic hyperthyroidism
tx for hyperthyroidism:
- antithyroid drugs (PTU, methimazole)
- ß-blockers
- RAI – I131
- thyroidectomy