Thyroid Flashcards
Graves disease etiology
type II hypersensitivity
anti-TSH receptor IgG that stimulates TSH receptor
causes T4 release from thyroid –> hyperthyroidism
Exophthalmos and pretibial myxedema classically seen in
hyperthyroidism
activation of fibroblasts
Tx of Graves disease
β-blockers
thiomide: inhibits peroxidase
radioiodine: ablates thyroid
Major complication of Grave’s disease
thyroid storm
arrhythmia, hyperthermia, vomiting, hypovolemic shock
Propylthiouracil useful in treating…
thyroid storm
inhibits peroxidase-mediated activities in thyroid
How does hyperthyroidism cause an increase in basal metabolic rate?
increase Na+/K+ ATPase expression
increase β1-receptor expression
Cholesterol and blood glucose status in hyperthyroidism
hypocholesterolemia
hyperglycemia
How does diffuse goiter occur in Graves
constant TSH stimulation of thyroid
=> thyroid hyperplasia and hypertrophy
TSH and free T4 labs in Graves
high T4 low TSH (negative feedback)
Multinodular goiter
etiology
complications
often due to relative iodine deficiency
may secrete T4 independent of TSH stimulation
Cretinism
hypothyroidism in neonates and infants
Cretinism due to genetic mutation is most often a result of this enzyme being mutated
thyroid peroxidase
Congenital hypothyroidism worldwide is most often due to
iodine deficiency
Myxedema in hypothyroidism most classically involves what areas
vocal cords (deepening of voice) tongue (macroglossia)
Most common cause of hypothyroidism in adults
Hashimoto thyroiditis
although it may transiently cause hyperthyroidism
Hashimoto thyroiditis HLA association
HLA-DR5
Hashimoto thyroiditis
etiology
presentation
autoimmune destruction of thyroid gland
presents as initial hyperthyroidism, followed by hypothyroidism
Bx results of Hashimoto thyroiditis
chronic inflammation germinal centers (increased risk for marginal B-cell lymphomas)
Complication of Hashimoto thyroiditis
marginal B-cell lymphoma
presents as enlarging thyroid in common who has normally been hypothyroid
Presentation of subacute granulomatous DeQuervain thyroiditis
after viral infection commonly
*tender thyroid with transient hyperthyroidism
does not need treatment, often resolves on its own
Reidel fibrosing thyroiditis may present similar to
anaplastic carcinoma of thyroid
both may be hard and invade local structures
Reidel more common in younger, anaplastic ca in older
Reidel fibrosing thyroiditis
presentation
very hard thyroid gland
invasion of local structures
often occurs in pts ~40 y/o
Thyroid carcinoma are typically:
hot/cold
on 131I radioactive thyroid scan
cold
cold nodules are most often not carcinomas though as well
Bx type when you want to look at the thyroid
fine-needle aspiration
because that boy bleeds like crazy
