Clinical: Thyroid

Question 1

Pathophysiology of cretinism.

Answer 1

Severely stunted physical and mental growth due to untreated congenital deficiency of thyroid hormones usually due to maternal hypothyroidism..

Question 2

Describe Myxedema coma (crisis).

Answer 2

Altered mental status, hypothermia, cardiogenic shock.

Often seen as a result of undiagnosed hypothyroidism patients exposed to a stressful event.

Question 3

Most common cause of primary hypothyroidism worldwide.

Answer 3

Iodine deficiency

Question 4

Most common cause of primary hypothyroidism in the US.

Answer 4

Hashimoto Thyroiditis (autoimmune)

Question 5

How is Hashimoto Thyroiditis diagnosed from an iodine deficiency hypothyroidism?

Answer 5

Both have elevated TSH and TRH

Hashimoto will have anti-microsomal, anti-TPO, or anti-Tg antibodies

Question 6

Describe Subacute Granulomatous Thyroiditis.

Answer 6

DeQuervain Thyroiditis

• painful goiter after viral infection (coxsackie or echo)
• initial hyperthyroidism follow by chronic hypothyroidism

Question 7

Tx for pain in DeQuervain Thyroiditis

Answer 7

Steroids cause rapid relief

NSAIDs may take longer (5 weeks)

Question 8

How is DeQuervain Thyroiditis distinguished from Graves?

Answer 8

Radioactive Iodine Uptake (RAIU)

• will be low in DeQuervain because the thyroid is low functioning
• high uptake in Graves because the thyroid is overactive

Question 9

Describe Post-Partum Thyroiditis.

Answer 9

High titers of anti-TPO Abs shortly after giving birth.

Question 10

Describe Sheehan Syndrome.

Answer 10

Post-partum pituitary necrosis leading to secondary hypothyroidism (panhypopituitarism, so other symptoms also occur).

Necrosis due to post partum hemorrhage

Question 11

Tx for any hypothyroidism.

Answer 11

Levothyroxine

-increase dose in pregnancy (~30%)

Question 12

Who should get treatment for hypothyroidism?

Answer 12

Patients with TSH of 4.5-10mlU/mL with a goiter
or
Patients with TSH greater than 10mlU/mL without a goiter

Question 13

Hallmark of Graves Disease.

Answer 13

Exophthalmos

Question 14

Describe the pathology of exophthalmos in Graves.

Answer 14

Lymphocytic infiltration into orbital tissue causes cytokine release and fibroblast formation. Fibroblast formation causes release of hyaluronic acid increasing the osmotic gradient.

Leads to swelling. Anterior displacement of the eye

Question 15

Tx for Graves Disease.

Answer 15

Medications:
1st line Methimazole (2nd line Propylthiouracil)

Radioactive Iodine:
used for larger glands in pts over 21 (if used in younger patients it might cause cancer)

Surgery: potassium iodide and antithryoid meds for 6 weeks pre-op

Question 16

Tx for ophthalmopathy in Graves Disease

Answer 16

High Dose Steroids

Question 17

Describe a Multi-nodular goiter and how it leads to hyperthyroidism.

Answer 17

Mainly caused by iodine deficiency. This leads to hyperplasia of the thyroid in response to a lower ability to produce TH. The TSH receptors on the thyroid become mutated and become spontaneously overactive. This causes massive TH release.

Question 18

What is Pemberton Sign?

Answer 18

Multinodular goiter causes obstruction of the SVC (superior vena cava) syndrome. Lack of blood drainage in the head and upper extremities occurs.

The patient is asked to raise arms about 90 degrees and the skin of the head and neck becomes red

Question 19

Tx of choice for Multinodular goiter.

Answer 19

Radioactive Iodine

Question 20

Diagnostic tool of choice for evaluating Thyroid Nodule.

Answer 20

Fine Needle Aspiration Biopsy

Question 21

Type of thyroid cancer secreting calcitonin.

Answer 21

Medullary

Question 22

Type of thyroid cancer with psammoma bodies.

Answer 22

Papillary

Question 23

Type of thyroid cancer with Hurthle Cells

Answer 23

Anaplastic

Question 24

What is Euthyroid Sick Syndrome.

Answer 24

Some acute, severe, illness causes abnormal thyroid tests. T3 and T4 are low, TSH is normal.

rT3 is elevated

Question 25

Tx of choice for thyroid disease in pregnancy.

Answer 25

Propylthiouracil