Pathoma: Thyroid Gland Flashcards
Thyroid development can stop at one of two places: ________________.
the tongue (leading to a tongue-base mass) or the neck (leading to an anterior neck mass)
Thyroid hormone stimulates increased basal metabolic rate by _______________.
increasing the expression of Na/K-ATPases
Thyroid hormone stimulates ____________ receptors.
beta-adrenergic
Hyperthyroidism can cause ________-glycemia and __________-cholesterolemia.
hyper (because TH is a counter-regulatory hormone); hypo
Graves’ disease results from IgG stimulation of ___________ receptors.
TSH
True or false: exophthalmos and pretibial myxedema result from increased T4.
False! There are TSH receptors on the fibroblasts of the eye and in the shins, so IgG stimulation leads to growth of glycosaminoglycans.
Histologically, what do thyroids with Graves disease look like?
The follicles will be enlarged, and there will be scalloping along the edges.
True or false: thioamide blocks an enzyme in the cytosol of thyroid follicular cells.
False. Thyroid peroxidase is in the colloid.
What are presenting signs of thyroid storm?
Arrhythmia, hyperthermia, hypovolemic shock, and vomiting
Relative iodine deficiency can cause _________________.
multinodular goiter
The historic term for congenital hypothyroidism is _________________.
cretinism (short stature, mental retardation, macroglossia, coarse facial features)
The most common enzymatic cause of congenital hypothyroidism is _____________.
thyroid peroxidase
Hypothyroidism results in _________________.
decreased basal metabolic rate (with weight gain despite normal intake), decreased cardiac output, and hypercholesterolemia
What HLA is associated with Hashimoto’s?
HLA-DR5
Describe the progression of Hashimoto’s.
Because the thyroid gets destroyed, T4 and T3 will initially be released (causing hyperthyroidism), but then the levels are exhausted and hypothyroidism ensues.
True or false: Hashimoto’s is caused by antithyroglobulin and antimicrosomal antibodies.
False. While these are present in someone with Hashimoto’s, they are a result of –not a cause of –Hashimoto’s.
A patient with Hashimoto’s presents with a greatly enlarged thyroid. What might be going on?
Marginal lymphoma. Hashimoto’s causes germinal centers to grow in the thyroid, which can raise risk of B-cell lymphoma.
True or false: a young woman presents with a disorder that causes tender thyroid; she is at risk of developing to hypothyroidism.
False. Subacute deQuervain granulomatous thyroiditis causes a tender thyroid, but it does not lead to hypothyroidism.
A non-tender, “hard as wood” thyroid is likely ________________.
Reidel fibrosing thyroiditis: a chronic inflammatory disorder that causes extensive fibrosis
Both Reidel fibrosing thyroiditis and anaplastic carcinoma can spread to local structures. What is the best way to distinguish the two?
Reidel is a disease of young people (particularly women) and anaplastic carcinoma is a disease of the elderly.
Thyroid nodules are much more likely to be _________.
benign
Decreased uptake in a thyroid nodule is suggestive of ______________.
non-functional adenoma or carcinoma (whereas increased uptake suggests Graves)
Follicular adenoma will present with what histologic pattern?
A capsule-encircled area that is more purple but still has follicles
There are four types of thyroid carcinoma –papillary, medullary, follicular, and anaplastic. Which is the most common?
Papillary (80%)
Papillary thyroid carcinoma presents with two distinct nuclear signs: ____________________.
Orphan Annie eyes (clearing of the nucleus) and nuclear grooves (purple lines in the nucleus)
Histologically, how do follicular carcinoma and follicular adenoma differ?
Both will have a fibrous capsule, but the carcinoma will invade through the capsule while adenoma will not.
Why can’t FNA differentiate between follicular adenoma and carcinoma?
Because both present with normal follicular cells in the center (where the needle will go). You need to see the borders to know which kind it is.
Medullary carcinoma is a proliferation of ____________ cells.
calcitonin-secreting cells
Medullary carcinoma presents as neoplastic cells stuck in ______________.
amyloid stroma (because the calcitonin can accumulate as amyloid)
RET mutations are indicative of ________________, prophylactically.
thyroidectomy
