Endocrine Flashcards

1
Q

First test in work-up of suspected acromegaly?

Second test if positive?

A

First test: IGF-1 level

Follow-up if positive: Oral glucose suppression test for GH (will fail to suppress in acromegaly)

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2
Q

Most common primary pituitary tumor?

A

Prolactinoma

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3
Q

When do prolactinomas require treatment?

What is the treatment?

A

Symptomatic or >1 cm in size

Treatment: DA agonists (e.g. cabergoline, bromocriptine) if <3 cm, larger goes to surgery

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4
Q

HPG axis hormone levels in Klinefelter syndrome?

A

Testosterone: low

FSH/LH: elevated (lack of negative feedback from testosterone)

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5
Q

Kallman syndrome

A

Hypogonadotropic hypogonadism (pubertal failure) + anosmia

Migration defect in GnRH-secreting and olfactory neurons

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6
Q

Key difference between primary and secondary adrenal insufficiency?

A

Primary: loss of glucocorticoid and mineralocorticoids, +hyperpigmentation (ACTH stimulating MSH receptors)
Secondary: loss of glucocorticoids only (mineralocorticoids regulated by RAAS, not ACTH)

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7
Q

Menstrual irregularity in PCOS? Cause?

A

Long, irregular periods.

Excess androgen converted to estrogen, prolonging the proliferative phase.

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8
Q

Potential cause of rapid-onset hirsuitism +/- virilization in women?
Test?

A

Androgen-secreting neoplasm
Test: serum testosterone and DHEAS (dehydroeplandrosterone, produced by adrenal neoplasm and converted to testosterone peripherally)

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9
Q

Who should get surgery for primary hyperparathyroidism?

A
  1. Symptomatic hypercalcemia
  2. Complications (osteoporosis, stones, renal dysfunction)
  3. High risk for complications (Ca2+ >1 mg/dl over normal, high urine calcium excretion, age under 50)
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10
Q

Tumors in MEN1? MEN2A? MEN2B?

A

MEN1: 3 P’s

  1. Primary hyperparathyroidism
  2. Pituitary tumors
  3. Pancreatic endocrine tumors (esp. gastrinomas)

MEN2A: 2 P’s, 1 M

  1. Pheochromocytoma
  2. Primary hyperparathyroidism
  3. Medullary thyroid cancer

MEN2B: 1 P, 3 M’s

  1. Pheochromocytoma
  2. Medullary thyroid cancer
  3. Mucosal neuroma
  4. Marfanoid habitus
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11
Q

Pheochromocytoma and thryoid storm can both lead to dangerous hypertension during surgery. What is a key difference?

A

Thyroid storm will have fever, pheo will not

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12
Q

Initial medical treatment for pheochromocytoma

A

Alpha blocker followed by beta blocker

Need to make sure alpha is block first so don’t see unopposed alpha vasoconstriction with beta block

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13
Q

Most common cause of primary adrenal insufficiency?

A

Autoimmune adrenalitis

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14
Q

Initial treatment of hyperosmolar hyperglycemic state

A
  1. Aggressive hydration with NS (regardless of sodium, due to fluid deficit due to polyuria, can give 1/2 NS later)
  2. IV insulin + potassium
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15
Q

Correction for sodium in hyperglycemia

A

Add 2 mEq/L Na+ for every 100 mg/dl glucose is above 100

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16
Q

Sign of glucagonoma on exam

A

Necrolytic migratory erythema: erythematous papules/plaques on face, limbs, and perineum, that enlarge/coalesce over 2 weeks, then develop central clearing and blistering with crust and scale

17
Q

Cause of “bronze diabetes”

A

Hereditary hemochromatosis (iron deposition in skin and pancreas, also deposits in liver and other organs)

18
Q

Major cause of death in hereditary hemochromatosis

A

Cirrhosis and Hepatocellular carcinoma (20x general population)

19
Q

Oral antihyperglycemics with highest risk of hypoglycemia?

A

Sulfonylureas (e.g. glipizide, gliclazide, or glimepiride)

20
Q

Oral antihyperglycemics that can help with weight loss?

A

GLP-1 agonists (e.g. exenatide)

21
Q

Oral antihyperglycemics that can lead to heart failure?

A

Thiazolidenidiones (e.g. pioglitazone)

22
Q

Initial tests in a thyroid nodule

A

TSH and ultrasound

23
Q

Treatment for thyroid storm

A
  1. Propanolol
  2. Thionamides (e.g. propylthiouracil, PTU)
  3. Iodine (blocks thyroid hormone delease, delay 1 hour after PTU)
  4. Glucocorticoids (decrease T4 -> T3 conversion)
24
Q

Calcium disturbances in thyroid disease

A

Hyperthyroidism activates osteoclasts (bone loss), bone resorption frees calcium, excess calcium excreted in urine (hypercalciuria, stones).

Serum calcium usually normal due to renal excretion and decreased vitamin D activation.

25
Q

Blood pressure in thyroid disease

A

Hyperthyroid: systolic HTN due to increase cardiac output

Hypothyroid: diastolic hypertension due to increased resistance and renal dysfunction

26
Q

Rare but serious reaction to thionamides (PTU, MMI)

A

Agranulocytosis

(If patient on these drugs comes in with fever and sore throat, immediately stop drug and get a WBC count to check for agranulocytosis)

27
Q

Most common form of thyroid cancer?

A

Papillary thyroid cancer

28
Q

Pathologic findings in papillary thyroid cancer on FNA

A

Psammoma bodies: grainy, lamellated calcifications

P for Papillary and Psammoma

29
Q

More aggressive but still common thyroid cancer?

A

Follicular thyroid cancer (2nd most common, more invasive, can metastasize)

30
Q

Pathologic findings in follicular thyroid cancer on FNA

A

Indistinguishable from follicular adenoma (many follicular cells in clusters and microfollicles).

Need excisional biopsy of entire nodule to diagnose (invasion in cancer, not in adenoma)

31
Q

Thyroid cancer that secretes calcitonin?

A

Medullary thyroid cancer (of parafollicular C cells)

32
Q

Additional tests needed in patient with medullary thyroid cancer?

A

Plasma fractionated metanephrine assay for pheo.

MEN2 testing (RET proto-oncogene)

33
Q

Effect of high titers of anti-TPO antibodies independent of whether patient is euthyroid or hypothyroid?

A

Increased risk of miscarriage

34
Q

Diagnostic tests for adrenal insufficiency

A

A.m. cortisol, ACTH level, ACTH/cosyntropin stimulation test

35
Q

Normal TSH and T4 but low T3 in a critically ill patient

A

“Euthyroid sick syndrome” or “low T3 syndrome” - due to decreased conversion of T4 to T3 in a sick patient

36
Q

What fibers are damaged in diabetic neuropathy to cause different symptoms?

A

Small fiber axonopathy causes positive symptoms: pain and paresthesias

Large fiber axonopathy causes negative symptoms: numbness, loss of proprioception, hyporeflexia

37
Q

Levels of DHEAS, LH, and T in:
Androgen-producing adrenal neoplasms?
Androgen-producing ovarian neoplasms?

A

Adrenal: elevated DHEAS and T, decreased LH
Ovarian: normal DHEAS, elevated T, decreased LH