EOR endocrine part 2

Question 1

What is the MCC of hyperthyroidism?

Answer 1

Graves’ disease

Question 2

What is Graves’ dz?

Answer 2

Diffuse goiter with hyperthyroidism, exophthalmos, and pretibial myxedema

Question 3

Etiology of Graves’ dz

Answer 3

Caused by circulating antibodies that stimulate TSH receptors on follicular cells of the thyroid

Question 4

Female to male ratio of Graves’ dz

Answer 4

6:1

Question 5

What specific physical finding is associated with Graves’?

Answer 5

Exophthalmos

Question 6

How is the dx made of Graves’ dz?

Answer 6

Increased T3, T4, and anti-TSH receptor antibodies
Decreased TSH
Global uptake of I131 radionuclide

Question 7

Name tx option modalities for Graves’ dz

Answer 7

Medical blockade: iodide, propranolol, PTU, methimazole, Lugol’s solution (potassium iodide)
Radioiodide ablation: most popular therapy
Surgical resection: bilat subtotal thyroidectomy

Question 8

What are the possible indications for surgical resection in Graves’ dz?

Answer 8

Suspicious nodule
If pt is noncompliant or refractory to medicines
Pregnant
A child
If pt refuses radioiodide therapy

Question 9

What is the major complication of radioiodide or surgery for Graves’ dz?

Answer 9

Hypothyroidism

Question 10

How does PTU work?

Answer 10

Inhibits incorporation of iodine into T4/T3 (by blocking peroxidase oxidation of iodide to iodine)
Inhibits peripheral conversion of T4 to T3

Question 11

How does methimazole work?

Answer 11

Inhibits incorporation of iodine into T4/T3 only

Question 12

Define primary hyperparathyroidism

Answer 12

Increased secretion of PTH by parathyroid gland(s); marked by elevated calcium, low phosphorous

Question 13

Define secondary hyperparathyroidism

Answer 13

Increased serum PTH resulting from calcium wasting caused by renal failure or decreased GI calcium absorption, rickets, or osteomalacia; calcium levels are usually low

Question 14

Define tertiary hyperparathyroidism

Answer 14

Persistent HPTH after correction of secondary hyperparathyroidism; results from autonomous PTH secretion not responsive to the normal negative feedback due to elevated calcium levels

Question 15

What are the methods of imaging the parathyroids?

Answer 15

Surgical operation
U/s
Sestamibi scan
TI (technitium)- thallium subtraction scan
CT scan/MRI
A-gram (rare)
Venous sampling for PTH (rare)

Question 16

What are the indications for a localizing preoperative study?

Answer 16

Reoperation for recurrent hyperparathyroidism

Question 17

What is MCC of primary hyperparathyroidism?

Answer 17

Adenoma (>85%)

Question 18

What are the etiologies of primary HPTH and percentages?

Answer 18

Adenoma (~85%)
Hyperplasia (~10%)
Carcinoma (~1%)

Question 19

What are the RFs for primary hyperparathyroidism?

Answer 19

FHx
Men-I
MEN IIa
Irradiation

Question 20

What are the s/sx of primary HPTH hypercalcemia?

Answer 20

Stones: Kidney stones
Bones: bone pain, pathologic fx, subperiosteal resorption
Groans: muscle pain and weakness, pancreatitis, gout, constipation
Psychiatric overtones: depression, anorexia, anxiety
Other sx: polydipsia, wt loss, HTN, polyuria, lethargy

Question 21

What is the 33-to-1 rule?

Answer 21

Most pts with primary HPTH have a ratio of serum chloride to phosphate greater than or equal to 33

Question 22

What plain XR findings are classic for HPTH?

Answer 22

Subperiosteal bone resorption

Question 23

How is primary HPTH diagnosed?

Answer 23

Labs- elevated PTH (hypercalcemia, decreased phosphorous, increased chloride)
Urine calcium should be checked for familial hypocalciuric hypercalcemia

Question 24

What is familial hypocalciuric hypercalcemia?

Answer 24

Familial (autosomal dominant) inheritance of a condition of asymptomatic hypercalcemia and low urine calcium, with or without elevated PTH
In contrast, hypercalcemia from HPTH results in high levels of urine calcium

Question 25

DDx of hypercalcemia

Answer 25

``` Calcium overdose Hyperparathyroidism Hyperthryoidism Hypocalciuric hypercalcemia Immobility/iatrogenic (thiazide diuretics) Metastasis/milk alkali syndrome Paget's disease Addison's disease/acromegaly Neoplasm Zollinger-Ellison syndrome Excessive vit D Excessive vit A Sarcoid ```

Question 26

What is the initial medical tx of hypercalcemia (primary HPTH)?

Answer 26

Medical- IVF, furosemide- NOT thiazide diuretics

Question 27

Although most recommend surgery for asymptomatic primary HPTH, when is it considered mandatory?

Answer 27

Renal insufficiency (CR decreased by 30%) Osteoporosis Age <50 Calcium >1 mg/dL above upper limit of nl Hypercalciuria (>400 mg/day Ca excretion)

Question 28

What is the definitive tx for primary HPTH resulting from hyperplasia?

Answer 28

Neck exploration removing all parathyroid glands and leaving at least 30 mg of parathyroid tissue placed in the forearm muscles

Question 29

What is the definitive tx for primary HPTH resulting from parathyroid adenoma?

Answer 29

Surgically remove adenoma (send for frozen section) and bx all abnormally enlarged parathyroid glands

Question 30

What is the definitive tx for primary HPTH resulting from parathyroid carcinoma?

Answer 30

Remove carcinoma, ipsilateral thyroid lobe, and all enlarged LNs

Question 31

What is the definitive tx for secondary HPTH?

Answer 31

Correct calcium and phosphate; perform renal transplantation

Question 32

What is the definitive tx for tertiary HPTH?

Answer 32

Correct calcium and phosphate Perform surgical operation to remove all parathyroid glands and reimplant 30-40 mg in the forearm if refractory to medical tx

Question 33

What must be ruled out in the pt with HPTH from hyperplasia?

Answer 33

MEN type I and MEN type IIa

Question 34

What carcinomas are commonly associated with hypercalcemia?

Answer 34

``` Breast CA metastases Prostate CA Kidney CA Lung CA Pancreatic CA Multiple myeloma ```