Thyroid gland path Flashcards
a rare form of congenital hypothyroidism includes inborn errors of thyroid metabolism . . called what
dyshormonogenetic goiter
Genetic susceptibility to Graves is linked to polymorphisms in what genes
- CTLS4
- PTPN22
- HLA-DR3
Normally, T3 and T4 cross the placenta and are critical for what?
fetal brain development
Laboratory findings in Graves
- low TSH
- high free T4 and T3
- radioiodine scans show a diffusely increased uptake
Long laundry list of symptoms of Myxedema
- slowing of physical and mental activity
- initial: generalize fatigue, apathy, and mental sluggishness which may mimic depression
- speech and intellectual functions are slowed
- listless, cold intolerant, and frequently overweight
- decreased sympathetics: constipation and decreased sweating
- skin: cool and pale
- Heart: reduced CO so shortness of breath and decreased exercise capacity
- increase in total cholesterol and LDH . . increases cardiovascular mortality
Hashimoto is caused by what?
breakdown in self tolerance of thyroid autoantigens
clues that lead you to POSSIBILITY of neoplastic nodule
- solitary
- younger
- males
- history of radiation to head and neck
Describe gross appearance of a thyroid adenoma
solitary, spherical, encapsulated lesion that is demarcated from the surrounding thyroid parenchyma by a well define intact capsule . .. helps distinguish from multinodular goider
Binding of thyroid hormone to its nuclear thyroid hormone receptor results in the assembly of what
a multiprotein hormone-receptor complex on thyroid hormone response elevements (TREs) in target genes
Ocular changes in thyrotoxicosis
- Wide staring gaze and lid lag (sympathetic overstimulation of superior tarsal muscle) . . also known as Muller’s muscle
- True thyroid opthalmopathy associated with poptosis ONLY in Grave’s disease
therapies for anaplastic carcinomas
No effective therapies
What does calcitonin do?
promotes the absorption of calcium by the skeletal system and inhibits the resorption of bone by osteoclasts
What drugs can cause primary hypothyroidism
- Lithium
- iodines
- methimazole
- propylthiouracil
- p-aminosalicylic acid
explain the pathogenesis of Granulomatous thyroiditis
- believed to be from an immune response triggered by a viral infection
- Majority of pts have hx of URI just before onset
- Seasonal incidence: peaking in summer
epidemiolgy and stats about thyroid nodules
- 1-10% of US adults
- significantly higher in endemic goitrous regions
- W>M
- incidence increases throughout life
- overwhelming are benign
- <1% of solitary thyroid nodules are malignant . . and most of the cancers are indolent
neuroendocrine neoplasm derived from the parafollicular cells (C cells)
medullary carcinoma
If a multinodular goiter grows behind the sternum and clavicles what is it called
intrathoracic or plunging goiters
Maternal thryoid hormone deficiency later in pregnancy?
does not affect normal brain development
What is the unique translocation and fusion gene found in 1/3 to 1/2 of follicular carcinomas
(2;3): PAX8-PPARG fusion
describe the radinuclide scan for follicular adenoma
-nonfunctioning adenoma take up less radioactive iodine than the normal thyrod parenchyma: “COLD NODULES”
What manifestations are among the earliest and most consistent features of thyrotoxicosis
cardiac manifestations
- elevated contractility and output
- tachycardia, palpitations, and cardiomegaly are common
- Arrythmias, particularly Afib, occur frequently but more common in older patients
- congestive heart failure may develop
Where is cretinism found
- regions where dietary iodine deficiency is endemic
- Himalayas, inland China, Africa, Mountainous areas
What are some factors that affect prognosis of papillary carcinoma
- Age (less favorable for those > 40)
- Extrathyroidal extension
- Presence of distant metastases
Morphology of medullary carcinoma
- Sporadic: typically a solitary nodule
- familial: often bilateral with multiple nodules
- tumor positive for calcitonin by immunohistochemistry
- Familial medullary cancers: multicentric C CELL HYPERPLASIA in the surrounding thyroid parenchyma
- Acellular AMYLOID DEPOSITS derived from calcitonin polypeptides are present in the stroma in many cases