Thyroid disorders Flashcards
Autoimmune etiology
Painless thyroid enlargement
Predominant hypothyroid features
Positive TPO antibody
Hashimoto thyroiditis
Lymphocytic infiltrate with well-developed germinal centers
Hürthle cells (large eosinophilic cells filled with granular cytoplasm)
represent follicular epithelial cells that have undergone metaplastic change in response to inflammation.
Hashimoto thyroiditis
Onset following a viral illness Painful thyroid enlargement(tender goiter) Transient hyperthyroid symptoms ↑ ESR & CRP ↓ Radioiodine uptake
Subacute granulomatous thyroiditis
Inflammatory infiltrate with macrophages & giant cells
↑ ESR & CRP
↓ Radioiodine uptake
Subacute granulomatous thyroiditis
Pretibial myxedema and ophthalmopathy are specific features of
Graves disease
caused by an autoimmune response directed against the TSH receptor that results in the accumulation of glycosaminoglycans within the affected tissues.
Pretibial myxedema and Graves ophthalmopathy
symptomatic hyperthyroidism with elevated serum free thyroxine and suppressed TSH levels
Graves
↓ Total & T4
↑ TSH
Primary hypothyroidism:
Thyroid dysgenesis
TSH resistance
↑ TSH
↑ Total & T4
Thyroid hormone (T4/T3) resistance
↓ Total & T4
↓ TSH
Central hypothyroidism (ex, panhypopituitarism)
↓ Total & T4
↑ TSH
Transient due to maternal exposure
Iodine excess or deficiency
TSH receptor–blocking antibodies
Antithyroid medications
the most common cause of primary congenital hypothyroidism. In this condition, TSH is elevated and thyroxine (T4) is low.
Thyroid dysgenesis
(hypoplasia, aplasia, ectopy)
*treatment with levothyroxine prevents the development of neurocognitive dysfunction.
Asymptomatic at birth, but weeks to months later the baby begins to develop
Lethargy, poor feeding
Enlarged fontanelle
Protruding tongue, puffy face, umbilical hernia
Constipation
Prolonged jaundice
Dry skin
Congenital hypothyroidism
Symptoms develop after maternal thyroxine wanes
Congenital hypothyroidism can eventually present with what 5 unique findings
Pot belly/ Enlarged fontanelle Protruding tongue puffy face umbilical hernia Dry skin
Transplacental transfer of TSH receptor–stimulating antibodies in a mother with Graves disease can cause
______ .
Symptoms include tachycardia and irritability
↑Total & T4
↓ TSH
transient neonatal hyperthyroidism (neonatal Graves disease).
↑Total & T4
↓ TSH
Neonate
neonatal Graves disease (transient from mom)
In Congenital hypothyroidism, accumulation of \_\_\_\_\_ cutaneously and internally results in nonpitting edema (eg, "puffy" face) umbilical hernia protruding tongue large anterior fontanelle.
In addition, T4 is essential for normal ___ development and ______ during early life, and infants are at risk of severe and irreversible intellectual disability.
matrix substances
brain
myelination
Enlargement of a ______ can lead to obstructive symptoms (dysphagia, dysphonia, dyspnea)
Occurs, typically during times of heightened thyroid stimulation (eg, puberty, pregnancy).
lingual thyroid
Hyperthyroidism causes increased bone turnover with net ____
bone loss
___ stimulates osteoClast differentiation, increased bone resorption, and release of calcium.
MAJOR RISK FOR _____ AND BONE FRACTURES.
T3
OSTEOPOROSIS
___ stimulates OsteoBlast which then release RANK-L to stimulate Osteoclasts
PTH
*vs T3 which activates OsteoClast directly
Outline the steps to Hyperthyroid induced bone loss
starting with T3
T3 activates osteoclasts DIRECTLY Bone is reabsorbed Serum calcium elevated PTH is now lowered Less activation of Vit. D Increased Ca excretion/ Decreased Ca absorption Triggers Bone reabsorption
Outline the steps to Hypothyroidism (TSH resistance) starting with TRH
Hypothalamus releases TRH Ant. Pit releases TSH Thyroid gland TSH receptor is insensitive Low levels of T3/T4 excreted Triggers increased TRH and TSH release
Outline the steps to Thyroid Hormone resistance on PERIPHERAL TISSUE starting with TRH
Hypothalamus releases TRH Ant. Pit releases TSH Thyroid gland secretes T3/T4 Thyroid Hormone Receptor on peripheral tissue broken T3/T4 levels perceived as low Triggers increased TRH and TSH release