Mcphs Thyroid Disorders

Front 1

What is the major hormone secreted by the thyroid gland?

Back 1

Thyroxine T4

Front 2

T4 is converted where and into what?

Back 2

T4 is converted in the peripheral tissues to the more potent Triiodothyronine T3

Front 3

Only ____ T4 and T3 is biologically active.

Back 3

free (unbound)

Front 4

What synthesizes thyrotropin releasing hormone?

Back 4

Hypothalamus

Front 5

TRH is stimulated by what?

Back 5

decreased serum free T4 and T3, alpha-adrenergic agonists

Front 6

TRH inhibited by?

Back 6

increased serum free T4 and T3, alpha adrenergic blockers

Front 7

What produces thyrotropin or thyroid stimulating hormone and prolactin.

Back 7

Anterior pituitary

Front 8

What synthesizes and releases thyroid hormones: Thyroxine T4 and Triiodothyronine T3?

Back 8

Thyroid

Front 9

What is the best screening method for primary hypothyroidism and hyperthyroidism?

Back 9

Thyroid Stimulating Hormone (TSH) lab

Front 10

Measuring Free T3 is not a reliable lab for what?

Back 10

measuring hypothyroidism

Front 11

This is a glycoprotein synthesized only by the thyroid follicular cells. Testing for levels of this are most useful for monitoring patients after a total thyroidectomy - usually due to cancer.

Back 11

Thyroglobulin (Tg)

Front 12

This is used predominately to evaluate thyroid nodules?

Back 12

Thyroid ultrasound

Front 13

This is used to determine functional activity of gland, thyroid nodules :Hypofunctioning - cold versus Hyperfunctioning - hot

Back 13

Radioisotope Thyroid Scan

Front 14

If thyroid gland/nodules are hypofunctioning - cold this most likely means?

Back 14

Cancer

Front 15

This is the method of choice for evaluation of thyroid nodules.

Back 15

Fine needle aspiration cytology

Front 16

This measures how much radioactive tracer is absorbed by the thyroid, helps to identify causes of hyperthyroidism.

Back 16

Radioactive Iodine Uptake (RAIU)

Front 17

This is a deficient production of thyroid hormone by the thyroid gland. Worldwide it is the result of iodine deficiency.

Back 17

Hypothyroidism

Front 18

This is the failure of the thyroid gland to produce sufficient thyroid hormone. The most common form of hypothyroidism.

Back 18

Primary hypothyroidism

Front 19

This occurs due to TSH deficiency from the pituitary or sellar lesions, trauma, irradiation, TSH receptor defects.

Back 19

Secondary (Central) hypothyroidism

Front 20

This is due to a deficiency of thyrotropin-releasing hormone (TRH)

Back 20

Tertiary (Hypothalamic Failure)

Front 21

What are the causes of primary hypothyroidism?

Back 21

1. Chronic Autoimmune Thyroiditis (Hashimoto's Thyroiditis - most common)

2. Post Radiation

3. Thyroidectomy: Full or subtotal

4. Subacute Thyroiditis

5. Thyroid Dysgenesis

6. Iodiine Deficiency

7. Drugs: Antithyroid drugs, Lithium, Iterferon-alpha, Interleukin-2, Amiodarone

Front 22

How do drugs such as Antithyroid meds, lithium, interferon-alpha, interleukin-2, amiodarone cause primary hypothyroidism?

Back 22

Either by 1. Inhibiting release of T4/T3 or 2. blocking conversion of T4 to T3

Front 23

The following are symptoms of what?

Weakness, fatigue, lethargy, decreased energy, cold intolerance, dry skin, decreased sweating, hair loss, memory loss, constipation, weight gain, dyspnea, peripheral paresthesias, depression, anorexia, muscle cramps, arthralgias, menorrhagia.

Back 23

Hypothyroidism

Front 24

The following are signs of what?

Cold, pale, dry skin, course, dry sparse hair, dull facial expression, periorbital edema, eyelid droop, deepening of the voice, goiter, nonpitting edema (myxedema), delayed relaxation of the reflexes, slow speech, sleep apnea, joint effusions, hypothermia, hypertension, hypoventilation, macroglossia, cardiomegaly, dementia in the elderly.

Back 24

Hypothyroidism

Front 25

Sinus brady, flattened T waves, prolonged QT intervals, pericardial effusion, pleural effusion, decreased basal metabolic rate, hyponatremia, hypercholesterolemia, hypertriglyceridemia, normochromic normocytic anemia, megaloblastic anemia, and coagulopathies are associated with what?

Back 25

Hypothyroidism

Front 26

In diagnosing primary hypothyroidism:

1. TSH is?

2. Free T4 is?

Back 26

1. Increase TSH in primary hypothyroidism

2. Decreased T4 in primary hypothyroidism

Front 27

What is diagnostic of primary hypothyroidism?

Back 27

Increased TSH and low Free T4

Front 28

What diagnostic test excludes hypothyroidism?

Back 28

A normal TSH

Front 29

What will usually be positive in Hashimoto's Thyroiditis?

Back 29

Antithyroid antibodies

Front 30

This is an autoimmune process that destroys the thyroid gland by cell and antibody mediated immunologic processes. This often progresses to permanent hypothyroidism.

Back 30

Hashimoto's Thyroiditis

Front 31

On exam this will show the thyroid gland as being enlarged, firm, and it may have fine nodules. Pain and tenderness are not usually present. Depression and fatigue are common symptoms.

Back 31

Hashimoto's Thyroiditis

Front 32

With this TSH is suppressed, FT4 more elevated than T3, High titers of thyroid peroxidase antibodies, radioactive iodine uptake is zero, ESR elevated

Back 32

Hashimoto's Thyroiditis

Front 33

How do you Tx thyroiditis?

Back 33

Symptomatic with Propranolol

Front 34

What will be seen in the labs with Hashimoto's Thyroiditis?

Back 34

High TSH, Low FT4

Antithyroid Peroxidase and Antithyroglobulin antibodies: High

Front 35

What is the TX for primary hypothyroidism?

Back 35

Tx is with the synthetic thyroid hormone levothyroxine sodium (synthroid, levoxyl), adult replacement is 1-2mcg/kg/day with the average starting dose 50-100mcg/day, but lower for elderly patients.

Front 36

In primary hypothyroidism, when monitoring patient undergoing Tx, what do you look at?

Back 36

TSH

Front 37

In central hypothyroidism, when monitoring patient undergoing Tx, what do you look at?

Back 37

Free T4

Front 38

What is something important to know with medication TX and hypothyroidism?

Back 38

Do not switch between generic and brand formulations.

Front 39

This is longstanding profound untreated hypothyroidism. It is more common in the elderly and is typically precipitated by a concurrent illness.

Back 39

Myxedema coma

Front 40

What are the cardinal features of Myxedema coma?

Back 40

Hypothermia, respiratory depression and unconsciousness.

Front 41

How do you manage Myxedema coma?

Back 41

Ventilator support, rewarming - IV T4 replacement-initial bolus followed by steady daily replacement

IV Hydrocortisone is administered concurrently to avoid adrenal failure

Front 42

This is seen when there is mild elevations of TSH but normal serum free T4 concentrations and lack of overt clinical manifestations. The causes are similar to primary hypothyroidism. Patients are at high risk for progressing to overt hypothyroidism.

Back 42

Subclinical hypothyroidism

Front 43

What are the signs that a patient with subclinical hypothyroidism is at high risk for progressing to overt hypothyroidism?

Back 43

Age older than 60 years old

Presence of a Goiter

TSH > 10mU/L

Pregnant females

Presence of circulating antithyroid antibodies.

Front 44

How do you manage of subclinical hypothyroidism?

Back 44

Levothyroxine - but should be individualized for the patient.

Front 45

This occurs in critically ill patients, the thyroid tests can be abnormal without true thyroid dysfunction. Thyroid replacement therapy is typically not warranted with this.

Back 45

Euthyroid sick syndrome

Front 46

This should be suspected in patients with a history of pituitary or hypothalamic disease, when other pituitary hormone abnormalities are identified or when a pituitary or sellar mass is identified.

Back 46

Central hypothyroidism

Front 47

With this, TSH is normal or slightly low but within reference range - because it doesn't respond.

Low FT4 is diagnostic for this.

Back 47

Central hypothyroidism

Front 48

What is needed with central hypothyroidism to distinguish between hypothalamic and pituitary disease?

Back 48

MRI

Front 49

This is the hyperfunctioning of the thyroid gland resulting in elevated concentrations of free thyroid hormones, T4 and T3. Women are more commonly affected than men.

Back 49

Hyperthyroidism

Front 50

These are all causes of what?

Graves' disease
Toxic multinodular goiter
Solitary toxic adenoma
Iodine and drugs containing iodine (amiodarone, contrast imaging dyes)
Subacute thyroiditis
Painless thyroiditis
Thyroid hormone ingestion
Ectopic thyroid tissue (Struma ovarii)
TSH secreting pituitary adenoma

Back 50

Hyperthyroidism

Front 51

What do the following symptoms mean?

Nervousness, irritability, insomnia, hand tremor, excessive sweating, palpitations, weight loss, increased appetite, heat intolerance, pruritus, hyperdefecation, diarrhea, nausea/vomiting, oligomenorrhea, decreased libido, impotence, dyspnea on exertion

Back 51

Symptoms of Hyperthyroidism

Front 52

The following represent what?

Sinus tachycardia, elevated systolic BP, systolic ejection murmur, CHF or exacerbation of CAD, atrial fib, warm moist smooth skin, fine hair, eye stare, lid lag, eyelid retraction, conjunctival injection, oncholysis, goiter, fine distal tremor, brisk DTRs (hyper-reflexia), proximal muscle weakness, thyroid bruit or thrill

Back 52

Signs of hyperthyroidism

Front 53

This is the most common cause of hyperthyroidism. It is an autoimmune disorder characterized by autoantibodies binding to TSH receptors. Peak age of onset is 40&60 years, male to female ratio is 1:10.

Back 53

Graves' disease

Front 54

What are the clinical features that are specifically associated with Graves' disease?

Back 54

Goiter, Infiltrative Ophthalmopathy, Pretibial myxedema, acropachy

Front 55

What lab values point you toward a diagnosis of hyperthyroidism?

Back 55

A suppressed TSH with an elevated FT4 makes the diagnosis of hyperthyroidism.

Front 56

A TSH value of what excludes clinical hyperthyroidism?

Back 56

TSH > 0.1mIU/L

Front 57

Thyroid stimulating immunoglobulins (TSI) may present in what?

Back 57

Graves' disease

Front 58

Radioisotope thyroid scan may detect what?

Back 58

hyperfunctioning (hot) nodules

Front 59

Radioactive Iodine Uptake (RAIU) is usually ___________ with hyperthyroidism?

Back 59

Increased

Front 60

What are three treatment options for hyperthyroidism?

Back 60

1. Antithyroid medications

2. Radioactive iodine ablation therapy

3. Subtotal thyroidectomy

Front 61

What can be used for symptomatic relief of hyperthyroidism?

Back 61

Beta-Adrenergic blocking medications - relieve tachycardia, termors and anxiety. Long acting are preferred - Propranolol, Atenolol, Metoprolol

Front 62

This is the preferred treatment for patients with Graves'?

Back 62

Radioactive Iodine Ablation

Front 63

These are thionamides: Inhibit thyroid peroxidase, block thyroid hormone synthesis? (2 specific drugs and what type of medication are they?)

Back 63

Antithyroid medications

1. Methimazole
2. Propylthiouracil

Front 64

Which antithyroid medication is recommended for pregnant patients?

Back 64

Propylthiouracil

Front 65

Subtotal thyroidectomy is typically reserved for which patients?

Back 65

Pregnant females who haven't responded to medications, patients who prefer this procedure, people with large goiters, and those patients with possible malignancy.

Front 66

What is something you have to do a few weeks after subtotal thyroidectomy?

Back 66

Obtain thyroid function studies to determine if hypothyroidism has occurred.

Front 67

If someone is taking antithyroid medications that inhibit thyroid peroxidase, and block thyroid synthesis, and they end up coming down with a fever or sore throat, what must be done?

Back 67

Patient must get in contact with clinician and a CBC must be ordered.

Front 68

This is an acute exacerbation of hyperthyroidism. It is marked by hypermetabolism and hyperadrenergic response = fever, delirium, N/V, diarrhea, CHF, arrhythmias, coma.

Back 68

Thyroid storm

Front 69

What is the TX for thyroid storm?

Back 69

Propylthiouracil (PTU) 300mg PO every 6 hours

Saturated solution of potassium iodide 1-2 drops every 12 hours

Propranolol to control adrenergic symptoms

Front 70

This is the second leading cause of hyperthyroidism. It is caused by nodular hyperplasia of the thyroid follicles. Usually seen in patients over age 50, arises from simple goiter. Goiter is often asymmetric, irregular and lumpy.

Back 70

Toxic multinodular goiter

Front 71

What is the treatment of choice for toxic multinodular goiter?

Back 71

Radioactive iodine ablation

Front 72

This is a single HYPERFUNCTIONING benign tumor (adenoma), almost always follicular in origin, typically presents as unilateral nodule >3cm in size, usually painless.

Back 72

Solitary toxic adenoma

Front 73

What is necessary to diagnose solitary toxic adenoma?

Back 73

Fine needle aspiration and cytology

Front 74

How do you manage solitary toxic adenoma?

Back 74

Radioactive iodine ablation or surgery

Front 75

This is an autoimmune process that destroys the thyroid gland by cell and antibody mediated immunologic processes. It tends to be familial and more common in female. Histologically there is marked diffuse lymphocytic gland infiltration and variable degrees of fibrosis.

Back 75

Hashimoto's Thyroiditis

Front 76

Thyroiditis often progresses to permanent ________ ?

Back 76

hypothyroidism

Front 77

In thyroiditis what are seen with the various thyroid hormone levels?

Back 77

1. TSH is suppressed

2. FT4 is more elevated to T3

3. Thyroglobulin antibodies are High

4. Radioactive iodine uptake is Low - because it isn't hyperfunctioning

5. ESR is elevated

Front 78

What is the TX of thyroiditis?

Back 78

Symptomatic with propranolol

Front 79

This is the most common cause of a painful thyroid gland. It is self limited inflammation of the gland lasting from weeks to months. A viral infection is though to be the most common etiology, may have a prodrome of URI symptoms.

Back 79

Subacute Thyroiditis (DeQuervain's Thyroiditis, Giant Cell Thyroiditis, Granulomatous Thyroiditis)

Front 80

With this hyperthyroidism occurs due to the leakage of stored thyroid hormones from the inflamed thyroid gland.

Followed by transient euthyroid state and then hypothyroidism

Return to normal thyroid function usually occurs within 6-12 months in about 95% of patients.

Back 80

Subacute thyroiditis

Front 81

What are the clinical signs of subacute thyroiditis?

Back 81

On exam, thyroid with degrees of mild asymmetrical enlargement and tenderness.

Pain in thyroid radiating to the jaw.

Associated with malaise and low grade fever.

Front 82

What is seen with the following?

Toxic Phase - Decreased TSH, elevated serum thyroid hormones, thyroid antibodies negative, radioactive iodine uptake - low, elevated ESR.

Back 82

Subacute thyroiditis

Front 83

How do you TX the acute phase of subacute thyroiditis?

Back 83

1. ASA or NSAIDs for pain
2. Prednisone for severe pain to decrese inflammation
3. Beta adrenergic blockers for thyrotoxic symptoms

Front 84

A hypothyroidism with an increased TSH, and decreased FT4 and FT3 may require what in subacute thyroiditis treatment?

Back 84

May require Levothyroxine replacement

Front 85

This is an immune mediated process, it is an inflammation and destruction of the gland causing release of hormones resulting in hyperthyroidism. Affects up to 20% of women post partum usually within the first four months. As the gland is depleted of hormones, a hypothyroid state develops. Normal thyroid function typically occurs within a year.

Back 85

Postpartum thyroiditis (Silent lymphocytic thyroiditis)

Front 86

Patients with this may have a nontender, firm goiter. In the toxic phase there will be elevated thyroid hormones with suppressed TSH, Thyroid antibodies are positive in about 50%, RAIU is low, Beta adrenergic blockers are used to control the symptoms.

In the Hypothyroid phase of this you use replacement Levothyroxine, after euthyroid state achieved and maintained discontinue to see if recover has occurred.

Back 86

Postpartum thyroiditis

Front 87

With this the thyroid hormones are usually normal unless hyperthyroidism is present.

Back 87

Thyroid nodules

Front 88

What is used to help diagnose thyroid nodules?

Back 88

Cytology and Fine Needle Aspiration.

Cytology can help to differentiate benign from malignant lesions

Front 89

This is useful for documenting size of nodule(s), detecting nonpalpable nodules, identifying cysts. Can not differentiate between benign and malignant lesions

Back 89

Thyroid ultrasound

Front 90

This is used to determine functional activity of gland thyroid nodules: Hypofunctioning (cold) versus Hyperfunctioning (hot)

Back 90

Radiosotope thyroid scan in diagnosing thyroid nodules

Front 91

If you have a malignant fine needle aspiration biopsy with a thyroid nodules, what has to be done?

Back 91

Surgery

Front 92

If you have a nondiagnostic (inadequate) result from fine needle aspiration biopsy of a thyroid nodlue, what must be done?

Back 92

Repeat the procedure, or perform RAIU - Radionucleotide Iodine Uptake test

Front 93

Most of these are differentiated and arise from the follicular cells

Back 93

Thyroid cancer

Front 94

What is the most common type of thyroid cancer?

Back 94

Papillary

Front 95

This type of thyroid cancer is most common between the ages of 30-60, with a female to male ration of 3:1, it is least aggressive, metastasis is local (cervical lymph nodes), 10-year survival rates >90%

Back 95

Papillary thyroid cancer

Front 96

This is a thyroid cancer that is more common in the elderly and in regions of iodine deficiency. It is more aggressive and can involve metastases through bloodstream (bone, lung).

Back 96

Follicular thyroid cancer

Front 97

This is a thyroid cancer that arises from the thyroid parafollicular cells which secrete calcitonin. It is associated with MEN-Multiple Endocrine Neoplasia Syndrome, requires genetic testing of family members, Requires total thyroidectomy, Tends to be resistant to chemotherapy.

Back 97

Medullary thyroid cancer

Front 98

This is more common in the elderly, it is characterized by rapid, painful enlargement, it is highly aggressive and the survival is less than six months.

Back 98

Anaplastic thyroid cancer.

Front 99

With the following, what is most likely the diagnosis?

1. Hard, stone like consistency or fixation, cervical lymphadenopathy and hoarseness are most suggestive of this.

2. Thyroid function is usually normal

3. Surgery is required

4. Endocrinology follow up required.

Back 99

Thyroid cancer

Front 100

Total body scans with thyroid cancer are done at what intervals?

Back 100

6 and 12 months

Front 101

Total body scanning is discontinued after ____ negative scans when treating thyroid cancer?

Back 101

2

Front 102

In thyroid cancer, you follow ____ _________ as a tumor marker. A rising marker indicates tumor recurrence.

Back 102

Serum Thyroglobulin

Front 103

In thyroid cancer, medullary carcinoma follows serum calcitonin as a what?

Back 103

additional tumor marker.