Section 5: Prolactinoma, Acromegaly and Hormones of Reproduction

Question 1

Most accurate diagnostic test for prolactinoma

Answer 1

MRI of the brain

Question 2

Best initial therapy for prolactinoma

Answer 2

Dopamine agonists: Bromocriptine Cabergoline

Question 3

Why is DM common among those with acromegaly?

Answer 3

Because growth hormone acts as an anti-insulin

Question 4

Best initial test for acromegaly

Answer 4

Insulin-like growth factor (IGF)

Question 5

Why is GH not the best initial test for acromegaly?

Answer 5

Growth hormone (GH) level is not done first, because GH has its maximum secretion in the middle of the night during deep sleep. GH also has a short half-life.

Question 6

Most acurate test to diagnose acromegaly

Answer 6

Suppression of GH by giving glucose excludes acromegaly.

Question 7

What is the place of MRI in the diagnosis of acromegaly?

Answer 7

To locate the lesion

Question 8

Outline the Rx of acromegaly

Answer 8

• Surgical resection with transphenoidal removal cures 70 percent of cases
• Octreotide: Somatostatin has some effect in preventing the release of growth hormone
• Cabergoline or bromocriptine: Dopamine agonists inhibit growth hormone release
• Pegvisomant: This is a growth hormone receptor antagonist.

Question 9

Clinical features of Turner’s syndrome

Answer 9

• Short stature
• Webbed neck
• Wide-spaced nipples
• Scant pubic and axillary hair
• The XO karyotype prevents menstruation

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 3488-3490). . Kindle Edition.

Question 10

What is the etiopathogenesis of testicular feminization syndrome?

Answer 10

The absence of testosterone receptors results in no penis, prostate, or scrotum.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Location 3492). . Kindle Edition.

Question 11

Name two causes of primary amenorrhea

Answer 11

• Turner’s syndrome
• Testicular feminization syndrome

Question 12

Enumerate the causes of secondary amenorrhea

Answer 12

• Pregnancy
• Exercise
• Extreme weight loss
• Hyperprolactinemia
• Polycystic ovary syndrome

Question 13

Best initial tests for pheochromocytoma

Answer 13

• High plasma and urinary catecholamine levels
• Plasma-free metanephrine and VMA levels

Question 14

Most accurate test for pheochromocytoma

Answer 14

CT or MRI of the adrenal glands

Question 15

Rx outline for pheochromocytoma

Answer 15

• Phenoxybenzamine (alpha blockade) first to control blood pressure. Without alpha blockade, patients’ blood pressure can significantly drop intraoperatively
• Propranolol is used after an alpha blocker like phenoxybenzamine
• Surgical or laparoscopic resection

Question 16

What is the strongest indication for screening for DM

Answer 16

HTN

Question 17

Name the characteristics of MEN syndrome type 1 (Wermer’s syndrome)

Answer 17

• Parathyroid hyperplasia
• Pancreatic islet cell tumor
• Pituitary adenoma

Remember with 3 Ps (W looks like 3 rotated 90 degress anticlockwise)

Question 18

Name the characteristics of MEN syndrome type 2A (Sipple’s syndrome)

Answer 18

• Parathyroid hyperplasia
• Thyroid medullary cancer
• Pheochromocytoma

Question 19

Name the characteristics of MEN syndrome type 2B

Answer 19

• Thyroid medullary cancer
• Pheochromocytoma
• Mucocutaneous neuromas
• Ganglioneuromatosis of the colon
• Marfan-like habitus

Question 20

Name the anterior pituitary hormones and the hypothalmic hormones that control their release

Answer 20

• ACTH controlled by CRH
• GH controlled by GHRH
• TSH controlled by TRH
• LH controlled by GnRH
• FSH controlled by GnRH
• PRL controlled by Dopamine (inhibits)

ACTH = AdrenoCortiTropic Hormone

CRH = Corticotropin Releasing Hormone

FSH = Folicle Stimulating Hormone

GnRH = Gonadotropin Releasing Hormone

GH = Growth Hormone

GHRH = Growth Hormone Releasing Hormone

LH = Leutinizing Hormone

PRL = Prolactin

Question 21

Diagnosis:

HTN + Low renin + Low potassium

Answer 21

Hyperaldosteronism

Question 22

Confirmatory diagnostic test for hyperaldosteronism

Answer 22

CT scan of the adrenals

Question 23

Risk factors for osteoporosis

Answer 23

• Menopause
• Low BMI
• Family hx of osteoporosis
• Early ovarian failure
• Low calcium intake
• Smoking
• Nulliparity
• Alcohol
• High caffeine intake

(Source: S95)

Question 24

What are implications of prebreakfast, prelunch, predinner and bedtime glucose levels?

Answer 24

• Prebreakfast glucose level: Reflects predinner NPH dose
• Prelunch glucose level: Reflects prebreakfast regular insulin dose
• Predinner glucose level: Reflects prebreakfast NPH dose
• Bedtime glucose level: Reflects predinner regular insulin dose

Question 25

What are the time of onset, peak effect and duration of regular insulin

Answer 25

* Onset: 30-60 minutes * Peak effect: 2-4 hours * Duration: 5-8 hours

Question 26

What are the time of onset, peak effect and duration of lispro

Answer 26

* Onset: 5-10 minutes * Peak effect: 0.5-1.5 hours * Duration: 6-8 hours

Question 27

What are the time of onset, peak effect and duration of aspart

Answer 27

* Onset: 10-20 minutes * Peak effect: 1-3 hours * Duration: 3-5 hours

Question 28

What are the time of onset, peak effect and duration of glulisine?

Answer 28

* Onset: 5-15 minutes * Peak effect: 1.0-1.5 hours * Duration: 1.0-2.5 hours

Question 29

What are the time of onset, peak effect and duration of NPH (Neutral Protamine Hagedorn)?

Answer 29

* Onset: 2-4 hours * Peak effect: 6-10 hours * Duration: 18-28 hours

Question 30

What are the time of onset, peak effect and duration of detemir?

Answer 30

* Onset: 2 hours * Peak effect: No discernible peak * Duration: 20 hours

Question 31

What are the time of onset, peak effect and duration of glargine?

Answer 31

* Onset: 1-4 hours * Peak effect: No discernible peak hour * Duration: 20-24 hours

Question 32

Possible diagnoses: * TSH - low * T4 - high * RAIU - decrease

Answer 32

Subacute thyroiditis (hyperthyroid stage) Hashimoto thyroiditis (hyperthyroid stage) Exogenous T3/T4: levothyroxine Postpartum thyroiditis

Question 33

Possible diagnoses: * TSH - low * T4 - high * RAIU - increase

Answer 33

* Graves' disease * Toxic adenoma * Multinodular goiter

Question 34

Possible diagnoses: * TSH - low * T4 - decrease

Answer 34

* Pituitary hypothyroidism * Hypothalamic hypothyroidism

Question 35

What are the predominant estrogens in reproductive years and during menopause?

Answer 35

Under the stimulation of the leutinizing hormone (LH), the theca cells of the post-menopausal ovary produce androstenedione and testosterone. **Estrone**, a product of androstenedione conversion in adipose tissue, is the predominant estrogen in menopause. **Estradiol** is the most prevalent estrogen in the reproductive years, and estriol is made by the placenta during pregnancy. **Estrane is a minor estrogen**

Question 36

What is hungry bone syndrome?

Answer 36

Hypocalcemia following surgical correction of hyperparathyroidism in patients with severe, prolonged disease, as calcium is rapidly taken from the circulation and deposited into the bone.