Lec 7 Thyroid goiters

Question 1

What is most common cause of goiter world wide?

Answer 1

endemic iodine deficiency

Question 2

What are most common causes of goiter in the US?

Answer 2

• multinodular goiter

- autoimmune thyroid disease [hashimotos]

Question 3

What is a multinodular goiter?

Answer 3

• form of thyroid hyperplasia
• familial
• gradually progressive

Question 4

Who gets multinodular goiters?

Answer 4

women in middle years of life

Question 5

What do you see on histology in multinodular goiter?

Answer 5

abundant colloid; follicles of varying size lined by benign follicular epithelium; some fibrosis

Question 6

How can you confirm diagnosis of toxic multinodular goiter?

Answer 6

radioiodine scan

Question 7

What percent of thyroid nodules are malignant?

Answer 7

5%

Question 8

What is epidemiology of thyroid nodules?

Answer 8

female:male 4:1

seen in 4-7% of adult US population

Question 9

What are 3 most common types of thyroid nodules?

Answer 9

• colloid nodule [multinodular goiter]
• follicular adenoma
• thyroid cancer

Question 10

What are characteristic appearance of follicular adenomas?

Answer 10

benign neoplasms with well developed capsule around the tumor

Question 11

What is michael reese series?

Answer 11

of pts irradiated at age < 15
- 39% develop thyroid nodules
11% develop thyroid cancer
may appear decades after radiation

Question 12

What is best test to see if nodule is cancer?

Answer 12

fine needle aspirate

detects the majority of thyroid cancers

Question 13

What is most common type of thyroid cancer?

Answer 13

papillary carcinoma

Question 14

What is prognosis of papillary thyroid carcinoma?

Answer 14

relatively indolent; low mortality in younger patients

Question 15

What are prognostic factors for low mortality in papillary carcinoma?

Answer 15

• older age
• extrathyroidal tissue invasion
• cervical lymph node met

Question 16

What are 2 major genes associated with papillary carcinoma? mech?

Answer 16

• BRAF
• RET

both activate MAPK signalling

Question 17

What is mech of action sorafenib?

Answer 17

kinase inhibitor = target for metastatic thyroid cancer

Question 18

What type of cancer do you see orphan annie eye cells?

Answer 18

papillary carcinoma

Question 19

What are two histologic characteristics of papillary carcinoma?

Answer 19

• orphan annie eye cells
• psamomma bodies
• papillary architecture with nuclear pleiomorphism

Question 20

What is prognosis of follicular carcinoma?

Answer 20

• prone to hematonegous distant met –> lung and bone

- poor prognosis

Question 21

What do you see histologically in follicular carcinoma?

Answer 21

capsular invasion

Question 22

What type of thyroid cancer has rapid enlargement that causes dyspnea?

Answer 22

anaplastic carcinoma of thyroid –> invades or compresses trachea

Question 23

What is prognosis of anaplastic carcinoma?

Answer 23

highly lethal; media survival < 1 yr

invades local structures in neck and has distant mets

Question 24

Who gets anaplastic carcinoma?

Answer 24

elderly patients

Question 25

What do you see on histology in anaplastic carcinoma?

Answer 25

• de-differentiated cells
• spindle cell appearance
• lack of features of normal thyroid tissue [no colloid or follicular structures]

Question 26

What type of thyroid cancer has atypical cells without follicular clusters and elevated calcitonin?

Answer 26

medullary carcinoma of thyroid

Question 27

Which cells of thyroid make up medullary tumor?

Answer 27

calcitonin secreting C cells

Question 28

What is genetics/inheritance of medullary carcinoma of thyroid?

Answer 28

• inherited ret oncogen

- MEN type II [with pheochromocytoma and hyperparathyroidism]

Question 29

What is use of calcitonin in medullary carcinoma?

Answer 29

marker for diagnosis and recurrence

Question 30

What do you see on histology in medullar carcinoma of thyroid?

Answer 30

amyloid deposits; lack of follicular architecture