Thyroid Disorders - Cryar

Question 1

What are examples of thyroid disorders based on abnormal function?

Answer 1

thyrotoxicosis

hypothyroidism

Question 2

What are examples of thyroid disorders based on abnormal structure?

Answer 2

diffuse goiter
nodular goiter (solitary nodule or multi)
atrophy

Question 3

What are the most important and valid thyroid tests?

Answer 3

TSH
Free Thyroxine (FT4)

Question 4

What are the thyroid antibody tests testing for and for which diseases?

Answer 4

1) anitmicrosmal and antithyroglobulin - highly positive in chronic lymphocytic thyroiditis
2) thyroid stimulating Ig (TSIG) - marker for graves disease

Question 5

When is thyroglobulin test high and when is it low?

Answer 5

low - exogenous thyroid ingestion

high - thyrotoxicosis

Question 6

What is the main marker for recurrent thyroid cancer?

Answer 6

thyroglobulin tests

Question 7

Which nuclear thyroid tests are there?

Answer 7

1) radioactive iodine (I131) - scan for configuration or uptake for function
2) technetium scan - for configuration

Question 8

Why is an ultrasound good for seeing the thyroid?

Answer 8

it can see nodules < 1mm

Question 9

Why do we test TSH and not actual thyroid hormone levels for function?

Answer 9

bc a patient can be hyperthyroid or hypothyroid and have “normal” thyroid hormone levels - T3/T4 are very sensitive to proteins and thyroid binding globulin (pregnancy, oral contraceptives, low albumin)
TSH is not affected by TBG or proteins

Question 10

Why is TSH a sensitive test?

Answer 10

1) changes log rhythmically in response to change in thyroid hormone
2) can be supressed or elevated while the hormone is still in the normal range

Question 11

What is subclinical thyroid disease?

Answer 11

patients with normal thyroid hormone levels and abnormal TSH - subclinical referring to the fact that the symptoms are not evident to the doctor

Question 12

What can subclinical thyroid disease result in?

Answer 12

atrial fibrilation

osteoperosis

Question 13

What are the etiologies of thryotoxicosis?

Answer 13

Graves Disease
Toxic nodular goiter
toxic nodule
thyroiditis
exogenous

Question 14

What are the signs and symptoms of thyrotoxicosis?

Answer 14

nervousness
heat intolerance
palpitations
tremulousness
weight loss
weakness
diarrhea
enlarged thyroid
ophthalmopathy
warm, smooth skin
fine tremor
brisk reflexes
proximal weakness
tachycardia

Question 15

What is Graves disease?

Answer 15

Hyperthyroidism - due to immunoglobulin stimulation of the TSH receptor and produces a diffuse goiter

Question 16

What are some complications of graves disease?

Answer 16

1) ophthalopathy - an inflammatory condition of the periorbital tissue
2) pretibial myxedema

Question 17

How do you diagnos Graves disease?

Answer 17

1) clinical features - goiter, ophthalmopathy, Symptoms
2) thyrotoxicosis on lab data - undetectable TSH and elevated T4
3) diffuse, elevated I131 uptake
4) positive TSIG

Question 18

What are the consequences of thyroid associated ophthalmopathy?

Answer 18

1) due to thyrotoxicosis of any etiology - lid lag and widened palpebral fissure
2) inflammatory- conjuctival and periorbital edema and red eye
3) infiltrative - proptosis (double vision), lid retraction, compromise vascular supple to optic nerve

Question 19

What nerves are affected in Graves disease ophthalmopathy?

Answer 19

medial and inferior rectus - problems looking up/out and laterally

Question 20

What are the 3 treatment options for Graves disease?

Answer 20

1) radioactive Iodine (I131)
2) surgery
3) antithyroid medications

Question 21

How does I131 treat Graves?

Answer 21

the thyroid slowly stops working. Its painless and you get gradual development of hypothyroid

There is a temporary risk or rise in T4

Question 22

What is the benefit to using surgery to treat Graves and who should get it?

Answer 22

this option is for really sick and frail patients. It is good for QUICK resolution. You get hypothyroidism right away. (risk of hypoparathyroidism or recurrent laryngeal nerve damage)

Question 23

When toxic nodular goiter usually occur?

Answer 23

with known long-standing nodular goiter

Question 24

What is seen with I131 uptake on patients with toxic nodular goiter?

Answer 24

patchy uptake of I131

Question 25

How is toxic nodular goiter treated?

Answer 25

1) surgery | 2) I131 - less responsive to this than Graves disease

Question 26

What is toxic nodule?

Answer 26

solitary autonomous nodule suppressing the remaining thyroid tissue

Question 27

How is toxic nodule treated?

Answer 27

1) I131 | 2) surgery

Question 28

When is thyrotoxicosis usually seen and how is it treated?

Answer 28

It is secondary to thyroiditis | self-limited illness requiring symptomatic treatment

Question 29

What can thyrotoxicosis be indistinguishable from clinically?

Answer 29

Graves disease

Question 30

How can laboratory tests distinguish throtoxicosis from Graves disease?

Answer 30

on lab work thyrotoxicosis shows low I131 uptake and TSH = 0

Question 31

What are the 3 types of thyroiditis?

Answer 31

1) acute (bacterial, fungal) 2) subacute granulomatous (de Quervain's) 3) chronic lymphocytic (hashimoto's)

Question 32

What is the three phase response of chronic throiditis?

Answer 32

1) thyrotoxicosis 2) hypothyroidism 3) recovery or permanent hypothyroidism

Question 33

What is post-partum thyroiditis?

Answer 33

a variant of Hashimoto's

Question 34

What is the clinical course of post-partum thyroiditis?

Answer 34

1) hyperthyroidism (1-4 months after delivery lasting 2-8 weeks) 2) hypothyroidism (lasts 2-8 weeks) 3) recovery

Question 35

What are the clinical findings in subacute granulomatous thyroiditis or de Quervain's?

Answer 35

1) PAINFUL 2) preceded or associated with fever 3) elevated ESR 4) may have thyrotoxicosis with low I131 uptake

Question 36

How do you treat subacute granulomatous thyroiditis or de Quervain's?

Answer 36

Symptomatic 1) asprin or NSAIDs 2) propanolol 3) maybe steroids

Question 37

What is the typical outcome of de Quervain's?

Answer 37

usually self limited | 8-12 weeks

Question 38

What is another name for chronic lymphocytic thyroditis?

Answer 38

Hashimotos

Question 39

What are complications of Hashimotos?

Answer 39

1) hypothyroidism | 2) thyrotoxicosis

Question 40

What is seen clinically in exogenous thyrotoxicosis?

Answer 40

1) suppressed TSH and elevated FTI (free thyroid index) 2) normal or small thyroid 3) low thyroglobulin 4) low I131 uptake

Question 41

What are the types of euthyroid goiter?

Answer 41

1) endemic (areas of iodine deficiency) 2) sporadic (hereditary) 3) nodular 4) diffuse

Question 42

What are some clinical features of hypothyroidism?

Answer 42

1) lethargy and fatigue, bradycardia, thin hair 2) dementia, irregular menses 3) cold intolerance, dry coarse skin, pallor 4) weight gain, thick tongue 5) hoarseness, paresthesis 6) delayed relaxation of reflexes

Question 43

How is primary hypothyroidism diagnosed?

Answer 43

with elevated TSH

Question 44

How is secondary hypothyroidism diagnosed?

Answer 44

1) low T3/T4 | 2) inappropriately low TSH (normally the TSH should be elevated if the FTI is low)

Question 45

How do you treat hypothyroidism?

Answer 45

initiation of thyroxine

Question 46

what are some cautions to be aware of with initiation of thyroxine for hypothyroidism?

Answer 46

1) caution in elderly or those who have compensated heart disease 2) does the patient have schmidt syndrome? (autoimmune polyendocrine disorder)

Question 47

Why do we replace with T4 and not T3?

Answer 47

the body converts T4 to T3 in the exact amount the body needs

Question 48

Why is a thyroid scan usually not helpful for cancer?

Answer 48

thyroid cancer is usually a "cold nodule"

Question 49

What are the types of thyroid carcinomas?

Answer 49

1) papillary - most common and most indolent 2) follicular - less common and more aggressive 3) anaplastic - most aggressive of all cancers 4) medullary - sporadic or familial (MEN II)