B8.058 Prework 2: Thyroid Gland Pathology

Question 1

exogenous goitrogenic agents that cause hypothyroidism

Answer 1

calcium and fluorides in water

foods: cabbage, cassave, cauliflower, brussels sprouts, turnips

Question 2

endemic cretinism

Answer 2

hypothyroidism in newborns and in infancy, esp in endemic areas (central africa, new guinea)

Question 3

sporadic cretinism

Answer 3

agenesis or metabolic defects of the thyroid during infancy

iodine deficiency during intrauterine life and in infancy

Question 4

what is myxedema

Answer 4

connective tissue accumulation in subcutaneous space

• nonpitting
• hard
• NOT fluid (polysaccharides)

Question 5

clinical presentation of Hashimoto’s

Answer 5

goitrous enlargment of the thyroid gland
midcourse - hyperthyroidism
long standing - hypothyroidism
F:M, 5:1

Question 6

hashimoto on histo

Answer 6

thyroid gland starts looking like a lymph node

inflammatory cell infiltrate

Question 7

pathogenesis of Hashimotos

Answer 7

type 2(ish) hypersensitivity
IgG autoAb against colloid and thyroid cells + autoreactive T cells

Question 8

clinical course of inflammatory hypothyroidism conditions

Answer 8

De Quervains & Riedel’s

• may be accompanied by pain in the neck and fever
• initial hyperthyroidism, followed by a transient period of hypothyroidism
• usually recover without treatment

Question 9

histo of inflammatory hypothyroidism conditions

Answer 9

fibroblasts
lymphocytes
bands of collagen

Question 10

cause of death in Graves

Answer 10

high output cardiac failure
-increased HR, atria don’t have time to fill
treat with B blockers (propranolol)

Question 11

gross appearance of a thyroid w Graves

Answer 11

more than 2x normal weight

large, nodular appearing

Question 12

Graves on histo

Answer 12

white areas where colloid is rapidly reabsorped (resorptive droplets)
this is due to rapid metabolism of colloid to produce T3 and T4

Question 13

benign thyroid adenoma

Answer 13

solitary, discrete, small nodule (<4 cm)
usually a cold nodule
typically well circumscribed by a pseudocapsule
rarely a hot nodule

Question 14

follicular adenoma on histo

Answer 14

glandular looking structures, follicular appearance
surrounded by capsule, separated from normal thyroid tissue
DOES NOT infiltrate capsule

Question 15

epidemiology of papillary carcinoma

Answer 15

most common

70-80% of all malignant thyroid tumors

Question 16

course of papillary carcinoma

Answer 16

indolent growth (psammoma bodies, calcification)
metastasis to local cervical lymph nodes
90-95% survival at 20 yrs

Question 17

histo of papillary carcinoma

Answer 17

papillary structures

cytological abnormalities

Question 18

course of follicular carcinoma

Answer 18

15-20% of thyroid cancers
distant metastasis via hematogenous spread
80-95% survival at 10 yrs

Question 19

histo of follicular carcinoma

Answer 19

invades pseudocapsule
infiltrating margin
washed out nuclei

Question 20

characterize medullary carcinoma or the thyroid

Answer 20

5-10% of thyroid malignancies
derived from parafollicular (C) cells
releases calcitonin and other peptides
part of MEN 2 syndrome > can screen for RET mutations

Question 21

histo of medullary carcinoma

Answer 21

stromal amyloid composed of altered calcitonin molecules
B-pleated sheets
large, clear cells

Question 22

medullary carcinoma prognosis

Answer 22

65-95% survival at 5 years

Question 23

characterize anaplastic carcinoma

Answer 23

2-7% of thyroid malignancies
most aggressive type of thyroid cancer
worst prognosis, 5 year survival < 5%
commonly invades trachea
grows fast af

Question 24

anaplastic carcinoma on histo

Answer 24

small blue cells with hemorrhage
DOESNT LOOK LIKE THYROID TISSUES
poorly differentiated