Thyroid and Parathyroid

Question 1

Parafollicular C cells derived form………. produce……. which does what?

Answer 1

derived from neural crest, produce calcitonin (decr serum calcium)

Question 2

T3: ____ times as active as t4, half life= _____

Answer 2

3 times as active; 3 days half life

Question 3

PTU: prevents ______; crosses placenta -> ______; rare but dreadful _______

Answer 3

DIT, MIT coupling; crossess placenta -> cretinism; rare but dreadful aplastic anemia

Question 4

____, ____, ___ all block peripheral conversion of T4 to T3

Answer 4

PTU; Propranolol, Prednisone

Question 5

Wold Chaikoff effect: high __ doses do what? useful in what?

Answer 5

high I-doses (lugol’s, KI) inhibit TSH, useful in thyroid storm

Question 6

FNA cannot distinguish malignant/benign with ____ and ____; what do you need?

Answer 6

follicular and Hurthle cell; need tissue

Question 7

Most common thyroid cancer; what %?

Answer 7

Papillary throid CA (85%, P for popular)

Question 8

Papillary thyroid cancer:
Spread? How do nodes predict survival?
___% of adults and ___% of children are node positive

Answer 8

Lymphatic spread, but nodes don’t predict survival;

20% of adults, 80% of children node positive; 80% are multicentric

Question 9

psammoma bodes on path of what cancer? what does it represent?

Answer 9

papillary thyroid cancer, represents deposited calcium

Question 10

History of exposure to _____ incr risk of papillary thyroid cancer

Answer 10

radiation

Question 11

F:M ratio in papillary thyroid ca: ____

1/2 papillary thyroid cancer presents before age ___

Answer 11

3:1; age 40

Question 12

MACIS criteria for thyroid carcinoma

Answer 12

Mets, age (M>50, F>40 is worse), completeness of resection, invasiveness and size (>1.5cm generally means total thyroidectomy needed)

Question 13

Follicular thyroid CA:

___ Spread? ___% present with mets; F:M ratio ___? Present a older/younger? _____; Needle dx adequate? ___; Rx? ____

Answer 13

Spreads hematogenously; 60% present with mets; presents a little older (50s); also F:M 3:1; needle dx NOT adequate; generally do total thyroidectomy with ablative RI post-op

Question 14

Medullary thyroid CA (MTC): 20% have ____

Answer 14

MEN2 (tend to be bilateral, younger, worse prognosis)

Question 15

Amyloid on path of thyroid tissue….

Answer 15

Pathognomonic for medullary thyroid CA

Question 16

____ is used as provocative test for medullary thyroid CA

Answer 16

gastrin (incr calcitonin)

Question 17

This cancer originates from parafollicular C cells

Answer 17

Medullary thyroid CA

Question 18

RET proto-oncogene is diagnostic for __________

Answer 18

medullary thyroid CA

Question 19

Medullary thyroid CA Rx? what if node +?

Answer 19

Total thyroidectomy, neck dissection if node (+)

Question 20

Which more likely cancer- cold/hot nodule?

Answer 20

cold, duh

Question 21

1st step in work-up of thyroid nodule after H&P is ____

Answer 21

FNA (Every year)

Question 22

When to operate on thyroids when pregnant? ____;

Use radioactive iodine?

Answer 22

Operate in 2nd trimester if possible; no radioactive iodine during pregnancy

Question 23

Radioactive iodine only useful for __________

Answer 23

well-differentiated tumors (papillary and follicular)

Question 24

Super laryngeal n., external branch: motor _______ injury _____ sensory _____

Answer 24

motor to cricothyroid muscle, injury= loss of projection, high pitch; provides sensory to supraglottis

Question 25

Recurrent laryngeal n. innervates ______; bilateral injury= ____

Answer 25

innervates all of larynx except cricothyroid; bilateral injury= occluded airway

Question 26

Superior parathyroids from ____; inferior (and thymus) from ___; which more variable?

Answer 26

Sup- 4th pouch; inf/thymus from 3rd pouch; inferior more variable

Question 27

All parathyroids generally receive blood supply from _____

Answer 27

inferior thyroid artery

Question 28

Which is active/inactive? n-terminal, c terminal

Answer 28

N terminal is active; c terminal is inactive in hormones (as with insulin)

Question 29

3 functions of PTH

Answer 29

incr calcium bind protein to incr gut absorption of Ca; incr kidney Ca absorption; incr PO4 loss

Question 30

Hyperparathyroidism; a/w _____ (gene) and h/o _____

Answer 30

prad oncogene; and h/o radiation exposure

Question 31

Hyperparathyroidism; what happens to Ca, ph,cl-:ph ratio

Answer 31

incr Ca; decr phos; Cl-:ph ratio > 3:1

Question 32

osteofibrosa cystica is pathognomonic for

Answer 32

hyperPTH

Question 33

Hyperparathyroidism; urina ca should be?

Answer 33

urine ca should be high; (r/o FHH= familal hypocalciuric hypercalcemia)

Question 34

Symptoms of most pts w hyperPTH

Answer 34

most patients are asymptomatic, found incidentally with high Ca

Question 35

IN hyperPTH, ___% have ____ adenoma(s)

Answer 35

85% have single gland adenoma (except in MEN where incr PTH is due to 4 gland hyperplasia)

Question 36

Palpable mass, very high Ca; what is it? what do you do?

Answer 36

Rare parathyroid adenocarcinoma: very high ca; resect widely

Question 37

MEN I

Answer 37

‘PPP’; Pancreatic islet cell tumor, pituitary tumor, hyperparathyroidism

Question 38

MEN IIA

Answer 38

‘2 MPH’ Medullary thyroid CA (nearly all patient) pheocromocytoma; hyperPTH

Question 39

MEN IIB

Answer 39

medullary thyroid CA (nearly all patients), pheochromocytoma, mucosal neuromas/marfan’s syndrome