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Flashcards in Pathology - endocrine Deck (31):
1

bilateral vs. unilateral adrenal atrophy

bilateral - exogenous steroid use
unilateral - primary adrenal adenoma/hyperplasia/carcinoma on unaffected side

bilateral hyperplasia - Cushing disease (pituitary adenoma)

2

hypoercortisolism screening tests

incr. free cortisol on 24 hr urinalysis
incr. midnight salivary cortisol

if decr. ACTH, then adrenal tumor
if incr. ACTH, then do high-dose dexamethasone suppression and CRH stimulation
if ectopic, then no suppression and no increase with CRH
if pituitary tumor, then suppression and increase with CRH

3

adrenal insufficiency diagnosis

serum electrolytes (low Na, high K)
random serum cortisol/ACTH
response to ACTH stimulation

metyrapone stimulation (usually blocks last step in cortisol synth): normal response = decr. cortisol, incr. ACTH. in adrenal insufficiency, ACTH remains decr. after test

4

Primary vs. secondary vs. tertiary adrenal insufficiency

primary - loss of gland function. hyperpigmentation (incr. MSH from incr. ACTH). assoc w/ autoimmunity or meningococcemia (W-F syndrome)

secondary - decr. ACTH secretion from pituitary. spares skin/mucosa pigment. aldosterone synth preserved

tertiary - chronic exogenous steroid use, precipitated by abrupt withdrawal

5

neuroblastoma

adrenal medulla, derived from neural crest, N-myc oncogene

CHILDREN, crosses midline! (Wilm's is unilateral)

dancing eyes, dancing feet

incr. homovanillic acid/vanillylmandelic acid in urine

6

pheochromocytoma

adrenal medulla, chromaffin cells, ADULTS

10%: malignant, bilateral, extra-adrenal, calcify, kids

seen w. NF1, MEN2A, MEN2B

5 P's: pressure, pain, perspiration, palpitations, pallor

tx: phenoxybenzamine (a blocker) followed by B-blockers

7

thyroid abnormality skin findings

hyperthryoid - pretibial myxedema, periorbital edema

hypothyroid - myxedema (facial/periorbital)

8

Cholesterol and thyroid abnormality

Hypothyroid - high LDL (low LDL receptor expression)

Hyperthyroid - low LDL (incr. LDL receptor expression)

9

Hypothyroid etiologies (4 pathologies)

Hashimoto - HLA-DR5, incr. non-Hodgkin lymphoma

Congenital hypothyroidism - fetus is pot-bellied, puffy-faced, protuberant tongue, poor brain development

Subacute thyroiditis - s/p flu-like illness, jaw pain, **tender thyroid**

Riedel thyroiditis - fibrotic invasion, IgG4 systemic dz, rock-like goiter

10

Hyperthyroid etiologies (4 pathologies)

Graves - most common, autoAbs stimulate thyroid/retroorbital fibroblasts/dermal fibroblasts

toxic multinodular goiter - focal patches, independent of TSH, incr. release of T3/T4

thyroid storm - stress-induced thyrotoxicosis, incr. alk phos, tx: 3 P's (propanolol, PTU, prednisolone)

Jod-Baselow - thyrotoxicosis s/p iodine replacement

11

Thyroid cancer (3 main subtypes)

Papillary: empty appearing nuclei w/ central clearing, psammoma bodies, lymphatic invasion

Follicular: good prognosis, invades thyroid capsule

Medullary: from parafollicular C cells, produces calcitonin, hematogenous spread, MEN 2A, 2B

12

Thyroid surgery complications

- hoarseness: recurrent laryngeal nerve damage
- hypocalcemia: removal of parathyroid glands
- transection of recurrent & superior laryngeal nerves: occurs during ligation of inferior and superior thryoid arteries (respectively)

13

Etiologies of hypoparathyroidism

Surgical excision of parathyroid glands

Autoimmune destruction

DiGeorge syndrome

PseudohypoPTH = Albright osteodystrophy, unresponsiveness of kidney to PTH, low Ca, shortened 4th/5th digits, short stature

14

PTH and Ca abnormalities

low PTH, low Ca = hypoparathyroidism

low PTH, high Ca = exogenous Ca intake

high PTH, low Ca = secondary hyperparathryoid (chronic renal failure, low Vit. D)

high PTH, high Ca = hyperplasia, adenoma, carcinoma

15

Hyperparathyroidism

Primary vs. secondary vs. tertiary

Primary: adenoma/hyperplasia, incr. PTH, serum Ca, urine Ca, alk phos, cAMP. look for stones, bones, groans, psych overtones

Secondary: chronic renal dz or low Vit. D = low Ca, high PO4, high alk phos, high PTH

Tertiary: refractory hyperPTH from chronic renal disease. extremely high PTH, elev. Ca

16

Bone changes with primary hyperparathyroidism

Osteitis fibrosa cystica - cystic bone spaces filled with brown fibrous tissue

deposited hemosiderin from hemorrhages

bone pain!

17

Treatment for prolactinoma

Dopamine agonists - bromocriptine, cabergoline

18

Acromegaly diagnosis

incr. IGF-1, failure to suppress serum GH following oral glucose tolerance test

tx: octreotide, pegvisomant (GH receptor antagonist)

19

Treatment for both diabetes insipidus

Central DI: intranasal desmopressin, hydration

Nephrogenic DI: HCTZ, indomethacin, amiloride

20

Water deprivation test

Central DI: incr. in urine osmolality only with ADH administration

Nephrogenic DI: minimal change in urine osmolality, even with ADH administration

21

SIADH causes

ectopic ADH: small cell lung cancer
CNS disorders/head trauma
Drugs (cyclophosphamide)
Pulmonary disease

tx: fluid restriction, IV hypertonic saline,- vaptans

22

Hypopituitary syndromes

Sheehan syndrome - ischemic infarct s/p postpartum bleeding

Empty sella syndrome - atrophy/compression of pituitary

Pituitary apoplexy - sudden hemorrhage of pituitary gland, often in presence of existing pituitary adenoma

23

three effects of insulin deficiency

decreased serum glucose uptake

increased protein catabolism

increased lipolysis

24

Sorbitol in diabetes mellitus

sorbitol accumulation in...

organs with aldose reductase

decr. or absent sorbitol dehydrogenase (retina, lens, kidney, and nerve cells)

25

Genetics in type 1 and type 2 diabetes

Type 1: low genetics (50% concordance), assoc w/ HLA-DR3/DR4

Type 2: high genetics (90% concordance)

26

Pancreatic histology in diabetes

Type 1: islet lymphocytic infiltrate

Type 2: islet amyloid polypeptide (IAPP) deposits

27

Glucagonoma

pancreatic alpha cells

4 D's: dermatitis (necrolytic migratory erythema), diabetes, DVT, depression

28

Insulinoma

low blood glucose but high C-peptide!

tx: surgical resection

29

Carcinoid syndrome

neuroendocrine cells (metastatic small bowel tumors), high secretion of 5-HT in non-GI locations

look for high 5-HIAA levels in urine and niacin deficiency

30

Zollinger-Ellison syndrome

gastrinoma, assoc w. MEN1

recurrent ulcers and diarrhea!

gastrin levels remain elevated after secretin admin (positive secretin stimulation test)

31

MEN syndromes

1: Parathyroid, Pituitary, Pancreas (gastrin, insulin, VIP, glucagon) (MEN mutation)

2A: Pheochromo, Medullary thyroid, parathyroid (RET, marfanoid)

2B: Pheochromo, Medullary thyroid, mucosal neuromas (RET, marfanoid)