2. MTB Step 3 - Thyroid Disease Flashcards
Cards Complete:
INTRODUCTION
What are the Similarities and Differences in presentation between Hypothyroidism and Hyperthyroidism?
GOITER
Which type of Thyroid Function is a Goiter associated with?
- You CANNOT determine an etiology only from the presence of a goiter.
- An enlarged gland can be associated with Hyperthyroidism, Hypothyroidism, or Normal Function of the thyroid.
SOLITARY THYROID NODULE
- What is the Best INITIAL Management step for a Solitary Thyroid Nodule AFTER drawing TSH & T4 levels and ruling out a hyperfunctioning gland?
Fine Needle Aspiration (FNA)
Ultrasound may be used to help place the needle
- If the Nodule is Cancer, it must be Surgically Removed by an expert; this is why you must ALWAYS answer TSH/T4 prior to biopsy*
- Do NOT biopsy lesions with increased thyroid function.*
HYPOTHYROIDISM
What is the Most COMMON Cause of Hypothyroidism?
“Burnt Out” Hashimotos Thyroiditis
HYPOTHYROIDISM
How do Hypothyroid patients present?
- Slow, Tired, and Fatigued
- Weight Gain
HYPOTHYROIDISM
What are the (2) Best INITIAL Tests for Hypothyroidism and what do they show?
- T4: DECREASED
- TSH: INCREASED
HYPOTHYROIDISM
What are the (2) possible Treatments for Hypothyroidism?
- T4 Replacement
- Thyroxine Replacement
T4 will be converted to T3 in the peripheral tissues, as needed.
HYPERTHYROIDISM
What are (4) causes of Hyperthyroidism?
- Grave’s Disease
- Silent Thyroiditis
- Subacute Thyroiditis
- Pituitary Adenoma
HYPERTHYROIDISM
What are the Findings on Physical Exam, RAIU, and what is the Treatment for each of the (4) causes of Hyperthyroidism?
see picture
HYPERTHYROIDISM
What are (3) additional Physical Findings in Grave’s Disease?
- Ophthalmopathy: The symptoms of ophthalmopathy include Exophthalmos (eyes are bulging) and Proptosis (lid is retracted).
- Dermopathy: This is thickening and redness of the skin just below the knee.
- Onycholysis: Occurring in only 10 percent of cases, this is separation of the nail from the nailbed.
HYPERTHYROIDISM
What are (3) parts to the Treatment of Grave’s Disease?
- Methimazole or PTU: give acutely to bring the gland under control (euthyroid state)
- Propranolol: to treat any Sympathetic Symptoms, such as Tremors, Palpitations, etc., if present
- Radioactive Iodine Ablation: done last, once gland and symptoms are under control
HYPERTHYROIDISM
BASIC SCIENCE CORRELATE
What is the Mechanism of Action (MOA) for both Methimazole and PTU?
Methimazole and PTU Inhibit Thyroperoxidase which, in turn, inhibit all of the following steps in thyroid hormone synthesis
- Oxidizing of Iodine;
- Putting Iodine on the Tyrosine molecule to make Monoiodotyrosine and Diiodotyrosine; and
- Coupling up of Mono- and Diiodotyrosine to make T4 and T3.
HYPERTHYROIDISM
What is the cause of “Silent” Thyroiditis and how does it present?
Autoimmune Disease
- Non-tender gland + Hyperthyroidism*
- No eye, skin, or nail findings*
HYPERTHYROIDISM
- What are the Diagnostic findings in “Silent” Thyroiditis?
- What is the treatment for “Silent” Thyroiditis?
- RAIU test is normal - gland is just leaking, not hyperfunctioning.
- +/- Antibodies to Thyroid Peroxidase and Antithyroglobulin Antibodies.
No treatment of “Silent” Thyroiditis
HYPERTHYROIDISM
What is the cause of Subacute Thyroiditis and how does it present?
Etiology: Viral (probably)
Presentation: Tender gland
