Primer 7 - Hypothyrodism and Thyroid Cancer

Question 1

What are five causes of cretinism?

Answer 1

1. Iodine-deficient diet
2. Thyroid-related enzyme deficiency
3. Thyroid developmental defect
4. Failure of thyroid descent during development
5. Transfer of antithyroid antibodies from the mother with an autoimmune disease to the fetus.

Question 2

What is the most common cause of hypothyroidism in the US?

Answer 2

Hashimoto Thyroiditis.

Question 3

What do we find in the physical exploration of Hashimoto Thyroiditis?

Answer 3

Hypothyroidism with painless goiter, dense infiltrate of lymphocytes into the thyroid.

Question 4

Which HLA genes are associated with Hashimoto Thyroiditis?

Answer 4

HLA-DR5

HLA-B5

Question 5

How do we diagnose Hashimoto Thyroiditis?

Answer 5

• Antithyroglobulin

- Antithyroid peroxidase antibodies

Question 6

How come people with Hashimoto Thyroiditis may have a short period of hyperthyroidism in the early phase of the disease?

Answer 6

As the inflammation begins, it causes destruction of follicle cells, and spilling of T3 and T4.

Question 7

Which type of lymphoma are Hashimoto patients are vulnerable to?

Answer 7

B cell lymphoma.

Question 8

What is another name for Subacute thyroiditis?

Answer 8

de Quervain.

Question 9

What is the progression of Subacute thyroiditis?

Answer 9

1. Early stages can be seen with hyperthyroidism due to inflammation of follicle glands that spill T3 and T4. Later transitions to hypothyroidism

Question 10

What is the classic clinical presentation of subacute thyroiditis?

Answer 10

Hypothyroidism with painful goiter.

Question 11

Which HLA gene is subacute goiter related?

Answer 11

HLA-B35

Question 12

What is suspected to be the cause of subacute thyroiditis?

Answer 12

Post-viral disease, like measles, mumps, coxackie, echo virus, etc.

Question 13

What is Riedel’s thyroiditis and what do we find in physical exploration?

Answer 13

Chronic inflammation of thyroid that leads to fibrous tissue. We find in physical exploration that they thyroid is fixed, hard rock-like thyroid. It is painless.

Question 14

What is the clinical presentation of Riedel’s thyroiditis? What do we see in histological finding?

Answer 14

Hypothyroid or euthyroid. Histology: Lots of fibrosis but we can find macrophages and eosinophils.

Question 15

What type of thyroiditis has lymphocytic infiltration on the thyroid?

Answer 15

Hashimoto.

Question 16

If we have an increase in radioactive iodine uptake in the thyroid, the type of cancers that can be suspected to have are:

Answer 16

Grave’s diases, mutlinodular, or single toxic adenoma.

Question 17

What is the most common type of thyroid cancer?

Answer 17

Papillary tumor.

Question 18

Which type of thyroid cancer has the best prognosis?

Answer 18

Papillary cancer.

Question 19

What do we see in the histological findings of papillary tumor of the thyroid?

Answer 19

Ground-glass appearance of nuclei : “Orphan Annie eye”. Also, psammoma bodies can be seen.

Question 20

What do we see in the histological findings of follicular carcinoma of the thyroid?

Answer 20

Uniform cuboidal cells lining the follicles. The follicle cells are the cancer but the cuboidal lining keeps them from getting away. It can invade thru the lining, which differentiates it from a follicular adenoma.

Question 21

What is the preferred way of metastasis of follicular carcinoma?

Answer 21

Hematogenously.

Question 22

What is medullary carcinoma of the thyroid and what substance does it like to secrete?

Answer 22

Proliferation of parafolicullar C cells. They secrete calcitonin.

Question 23

What 2 structures are most vulnerable in thyroid surgery?

Answer 23

1. Parathyroid glands: affects calcium levels

2. Recurrent laryngeal nerve: Hoarse voice

Question 24

What type of thyroid cancer has activation of receptor tyrosine kinases?

Answer 24

Papillary and medullary carcinoma.

Question 25

Which type of thyroid carcinoma is commonly associated with either a RAS mutation or a PAX8-PPAR gamma 1 rearrangement?

Answer 25

Follicular carcinoma.

Question 26

Which type of thyroid carcinoma is associated with rearrangements in RET oncogene or NTRK1?

Answer 26

Papillary carcinoma.

Question 27

Which type of thyroid carcinoma is associated with most common mutation in the BRAF gene?

Answer 27

Papillary carcinoma.

Question 28

What are some of the symptoms of hypothyroidism?

Answer 28

Cold intolerance, weight gain, constipation, lowering of the voice, menorrhagia, slowed mental and physical function, dry skin with coarse, brittle hair, reflexes showing slow return phase.