Pathology of the Thyroid

Question 1

WHat is Primary vs Secondary Hyperthyroidism

Answer 1

.

Question 2

What are the Signs and Symptoms of Hyperthyroidism?

Answer 2

Hypermetabolism
Enhanced epinephrine effect
Lid Lag- delay in drop of eyelid when Pt looks down
Atrial Fibrillation-likely
Thyroid Storm- Thyrotoxic Crisis (exreme hypermetabolism)

Question 3

What is the cause of Graves’ disease?

Answer 3

Autoimmune disease with prod of a IgG Ab against TSH receptor (TRAb) also (TSAb)
5:1 Fem to male ratio

Question 4

How is Graves’ disease diagnosed?

Answer 4

High T3 and T4(may still be within normal range bc there is much variability)
Low TSH

Question 5

What causes Opthalmopathy in Graves’ disease?

Answer 5

Lid Lag
Weak eye muscles
Ab against eye musc. and fibroblasts behind the eye
Excess Collagen and ground substance behind the eyeball

Question 6

What are peripheral findings in Graves’ Disease?

Answer 6

Myxedema AND Nodules confined to the anterior aspect of the lower legs

Question 7

What is seen grossly on the thyroid gland in Graves’ disease.

Answer 7

diffuse, symmetrical beefy red gland

Question 8

What is the Histological apearance of the Thyroid in Hyperthyroidism?

Answer 8

1) Hyperplastic Follacles with papillary infoldings

2) Pale Colloid resorption vacuoles (scalloping)

Question 9

What are the signs and symptoms of Hypothyroidism?

Answer 9

Slowing of Mind and Body
Mental slowness, fatigue, loss of interest
Myxedema => Coarsening of face, enlargement of tongue, puffy eyes, deepening and croaking voice

Question 10

What is Myxedema?

Answer 10

Accumulation of hydrophilic ground substance (amorphous gel-like substance) throughout the connective tissue of the body

Question 11

What is cretinism?

Answer 11

Hypothyroidism in infancy or childhood
Stunted Growth
Retarded mental devt
Delayed bone and tooth devt

Question 12

What are the dangers of Cretinism?

Answer 12

If you do not treat before 3rd week there will be delayed Mental and physical devt. (Irreversible)
US babies are screened for Hypothyroidism

Question 13

WHat is Hashimoto’s Thyroiditis?

Answer 13

Deficiency in Treg(regulatory T cells)
increase in cytotoxic T cells and activated B cells
HLA-Dr5

Question 14

What is the Gross appearance in Hashimoto’s Thyroiditis?

Answer 14

Diffusely enlarged thyroid that is firm and light in color (WBCs)

Question 15

What is the microscopic appearance of Hashimoto’s Thyroiditis?

Answer 15

Hyrthle cells
Abundant eosinophilic, granular cytoplasm
Metaplastic response to ongoing injury

Question 16

What is De-Quervain (Subacute Granulomatous) Thyroiditis

Answer 16

Secondary to a viral infection to 
Coxsackie and Adenovirus
also Echovirus and mumps
Transient Hyperthyroidism (weeks to months)
PAINFUL thyroiditis

Question 17

What is the pathology of De-Quervain Thyroiditis?

Answer 17

Granulomas with giant cells macrophages, lymphocytes and destroyed thyroid cells

Question 18

WHat is the effect of a goiter?

Answer 18

Thyroid’s ability to produce thyroid hormone is impaired => Inc TSH => Maint of euthyroid state

Question 19

What is the Progression of a goiter?

Answer 19

Non-tender enlargement of gland => becomes nodular over time

Question 20

What are the goiterogenic foods?

Answer 20

Cauloflower, Turnups, etc

Question 21

What is a Multinodular Goiter?

Answer 21

Increaed size and lobulation of gland

Differentiate from neoplasm

Question 22

What is the difference between Hot and Cold Nodules?

Answer 22

Cold: Palpable mass lesions that fail to take up radiolabeled Iodine (Higher chance of cancer)
Hot: Does take up Radiolabeled Iodine

Question 23

What is a thyroid adenoma?

Answer 23

No tendency to turn malignant

Solitary sperical encapsulated lesion that is demarkated from the surrounding thyroid tissue

Question 24

What is the most common type of thyroid cancer?

Answer 24

Papillary (65%)(prob. not die)
Follicular (25%) (50% will eventually die of it)
Medullary
Anaplastic (Almost all die quickly)

Question 25

What is papillary Thyroid Cancer?

Answer 25

Fibrovascular Stal with tumor cells
"Orphan Annie Eye" nuclei
-marginated chromatin and optically clear centers
-fixation artifact
Coffee Bean (folded nuclei)

Question 26

What is charicteristic of Follicular Thyroid Carcinoma?

Answer 26

Can Metastasise

Question 27

What gene is Medullary Thyroid CA?

Answer 27

RET

Question 28

What is Charicteristic of Anaplastic Thyroid CA?

Answer 28

Ugly on microscopic view 
-Large plieomorphic giant cells
-Spindle Cells with SA appearance
-Cytokeratin(+) but TG (-)
and clinically too!