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Flashcards in Endocrine Deck (51):
1

17-alpha hydroxylase deficiency
- Boys - ambiguous genitalia (phenotypically female), undescended testes
- Girls - lacks secondary sexual development

- High: MINERALOCORTICOIDS, blood pressure
- Low: cortisol, sex hormones, [K+]
- Labs: low androstenedione

2

21-hydroxylase deficiency
- Boys: salt wasting in infancy, precocious puberty in childhood
- Girls: virilization (clitoromegaly)

Most common CAH
Needed for MC and GC production (instead ACTH is shunted to sex hormones)
- High: sex hormones, [K+]
- Low: cortisol, mineralocorticoids, BP
- Labs: increased renin activity, increased 17-hydroxy-progesterone

3

11-beta-hydroxylase deficiency
- Boys: ?
- Girls: virilization

Low aldosterone, but high 11-deoxycorticosterone --> elevated BP
- High: sex hormones, BP
- Low: cortisol, [K+]
- Labs: decreased renin activity

4

Cortisol upregulates what R?

Alpha1 on arterioles --> increased sensitivity to NE and Epi --> elevated BP

5

Thyroid hormones up-regulate what R?

Beta1 on heart --> increased CO, HR, SV, and contractility
- Also increase Na+/K+ ATPase --> increased O2 consumption, RR, body temp --> increased basal metabolic rate

6

5'-deiodinase

Converts T3 to T4 in peripheral tissue
- Inhibited by PTU but NOT methimazole

7

Thyroid Peroxidase

- Oxidation and organification of iodide
- Couples monoiodotyrosine to di-iodotyrosine
- Inhibited by PTU and methimazole

8

Metyrapone Stimulation
- Adrenal insufficiency

Blocks 11-deoxycortisol --> cortisol (last step of cortisol synthesis)
- Normal: decreased cortisol, compensatory increase in ACTH and 11-deoxycortisol
- Primary adrenal insufficiency: ACTH increases, but 11-deoxycortisol remains decreased after test
- Secondary adrenal insufficiency: both ACTH and 11-deoxycortisol remain decreased after test

9

Waterhouse-Friderichsen Syndrome
- Septicemia, DIC, endotoxic shock

- Primary adrenal insufficiency due to adrenal hemorrhage
- NEISSERIA MENINGITIDIS

10

Conn Syndrome
- HTN, metabolic alkalosis, no edema

- Adrenal adenoma --> primary hyperaldosteronism
- Increased aldosterone, decreased renin (negative feedback)

11

How can fibromuscular dysplasia and atherosclerosis cause hyperaldosteronism?

- Activate JGA --> increased renin --> increased aldosterone

12

Neuroblastoma
- Kids - abdominal distension, firm/irregular mass that can cross the midline (vs. Wilms tumor)
- Opsoclonus-myoclonus syndrome ("dancing eyes-dancing feet")

- Most common tumor of adrenal medulla in children
- Originates from neural crest cells
- Increased HVA and VMA in urine
- Homer Wright rosettes
- Bombesin and NSE +
- N-myc oncogene overexpressed
- APUD tumor

13

Hashimoto Thyroiditis
- Hypothyroidism

- Ab: antithyroid peroxidase (antimicrosomal), antithryoglobulin
- HLA-DR5
- Increased risk of non-hodgkin lymphoma
- Histo: Hurthle cells, lymphoid aggregates w/ germinal centers

14

Congenital Hypothyroidism (Cretinism)
- Neonates/infants

Pot-bellied, pale, puffy-faced child with protruding umbilicus, protuberant tongue, and poor-brain development
- Short stature and skeletal abnormalities due to decreased growth hormone

15

Subacute Granulomatous Thyroiditis (de Quervain)
- Hypothyroid

- Follows viral infection
- Histo: granulomatous inflammation (macs and giant cell)
TENDER THYROID

16

Riedel Thyroiditis
- Hypothyroid

- Thryoid replaced w/ fibrous tissue w/ inflammatory infiltrate
- Mimics anaplastic carcinoma
- IgG4-related systemic disease
- Hard, rock-like painless goiter

17

Graves Disease
- Hyperthyroid

Ab: thyroid-stimulating Ig (IgG, type II HSN)
- Dermal fibroblasts --> pretibial myxedema
- T cells --> increase CKs (TNF-alpha, IFN-gamma) --> increased fibroblast secretion of hydrophilic GAGs --> exophthalmos
- Histo: tall, crowded follicular epi cells, SCALLOPED COLLOID
- Rx: beta blockers, thiomide (blocks peroxidase), radioiodine ablation, prednisone for severe opthalmopathy

18

Treatment of thyroid storm

Beta blockers (propanolol), PTU, corticosteroids (prednisolone), potassium iodide

19

Wolff-Chaikoff Effect

Excess iodine temporarily inhibits thyroid peroxidase --> decreased iodine organification --> decreased thyroid hormone

20

Jod-Basedow Phenomenon

Patient w/ iodine deficiency and partially autonomous thyroid tissue is given iodine --> thyrotoxicosis
- Opposite of Wolff-Chaikoff effect

21

What nerve runs with inferior thyroid artery?

Recurrent laryngeal nerve
- Risk of injury during thyroidectomy --> hoarseness

22

What nerve runs with superior artery?

Superior laryngeal nerve --> cricothyroid muscle

23

Papillary Carcinoma (Thyroid)
- Most common, excellent prognosis

- Orphan Annie nuclei, psammoma bodies, nuclear grooves
- Increased risk with RET and BRAF mutations and childhood irradiation

24

Follicular Carcinoma (Thryoid)
- Good prognosis

- Invades thyroid capsule and vasculature (vs. follicular adenoma)
- Uniform follicles
- Hematogenous spread
- RAS mutation

25

Medullary Carcinoma (Thyroid)

- Parafollicular "C" cells
-Neuroendocrine
- Produces calcitonin --> diarrhea, flushing
- Sheets of cells in AMYLOID STROMA (Congo red)
- Associated with MEN2A and MEN2B (RET)

26

Anaplastic Carcinoma (Thyroid)
- Very poor prognosis, older patients

- invades local structures --> dysphagia, respiratory compromise

27

Thyroid Lymphoma

Associated with Hash thyroiditis

28

Chvostek and Trousseau sign?

- HYPOPARATHYROIDISM
- Hypocalcemia
- Chvostek --> facial nerve
- Trousseau --> BP cuff

29

Pseudohypoparathyroidism Type 1A (Albright hereditary osteodystrophy)
- Shortened 4th/5th digit, short stature

- Unresponsiveness of kidney to PTH --> hypocalcemia despite increased PTH levels
- AD --> defective Gs protein alpha subunit --> end-organ resistance to PTH
- Must be inherited from mother (imprinting)

30

Pseudopseduohypoparathyroidism

- Findings of Albright hereditary osteodystrophy but without end-organ PTH resistance
- Defective Gs protein alpha subunit is inherited from father

31

Familial Hypocalciuric Hypercalcemia

Defective Ca2+ sensing receptor in multiple tissues
- Excessive renal Ca2+ reuptake --> mild hypercalcemia with hypocalciuria with normal/elevated PTH levels

32

Sheehan Syndrome
- Postpartum failure to lactate, absent menstruation, cold intolerance, loss of pubic hair

- Ischemic infarct of pituitary following postpartum bleeding (pituitary is much larger during pregnancy but there is no increase in blood flow --> increased susceptibility to hypoperfusion)

33

Empty Sella Syndrome
- Idiopathic, obese women

Atrophy or compression of pituitary

34

Pituitary Apoplexy
- Sudden onset severe HA, visual impairment (bitemporal hemianopia, diplopia due to CN III palsy), features of hypopituitarism

- Sudden hemorrhage of pituitary gland --> compresses normal tissue
- Often in presence of existing pituitary adenoma

35

Type 1 DM Antibodies

Glutamic acid decarboxylase antibodies

36

Most common cause of death in DM

MI

37

Nodules seen in diabetic nephron

Kimmelstiel-Wilson Nodules

38

Type 1 DM HLA

HLA-DR3 and DR4

39

Histology of T1DM vs. T2DM

T1DM: islet leukocytic infiltrate
T2DM: islet amyloid polypeptide deposits

40

Deadly infection in DKA?

Mucormycosis (Thizopus)

41

Treatment for DKA?

- IV fluids --> sugar in urine is diuretic (dehydrated)
- IV insulin
- K+ --> lost lots of K+ in urine (even though labs show hyper K+, plus insulin drives K+ into cells)
- Glucose if necessary

42

Hyperosmolar Hyperglycemia Nonketotic Syndrome
- Thirst, polyuria, lethargy, focal neuro defects (seizures), can progress to coma and death
- elderly T2 diabetic w/ limited ability to drink

- Profound hyperglycemia-induced dehydration (osmotic diuresis)
- Labs: hyperglycemia, increased serum osmolarity, no acidosis, no ketones
- Rx: aggressive IV fluids, insulin therapy

43

Presentation of glucagonoma?

- Dermatitis (necrolytic migratory erythema)
- Diabetes (hyperglycemia)
- DVT
- Declining weight
- Depression
Rx: octreotide, surgery

44

Presentation of insulinoma?

- Whipple triad: hypoglycemia, sx of hypoglycemia (lethargy, syncope, diplopia), and resolution of sx after normalization of glucose levels
- Labs: decreased blood glucose, increased C-peptide
- MEN1 syndrome

45

Presentation of somatostatinoma?

- Diabetes/glucose intolerance, steatorrhea, gallstones due to decreased secretion of secretin, CCK, glucagon, insulin, gastrin

46

Presentation of carcinoid syndrome?

- Recurrent diarrhea, cutaneous flushing, asthmatic wheezing, R-sided valvular heart DZ, pellagra (niacin deficiency), 5-HIAA in urine
- Only seen if tumor has spread out of GI tract
- ROSETTES
- Serotonin

47

Presentation of gastrinoma?

Abdominal pain (PUD), diarrhea (malabsorption)
- Gastrin levels remain elevated after administration of secretin
- MEN1

48

Presentation of VIPoma?

Watery diarrhea, hypokalemia, achlorhydria

49

MEN1

Pituitary adenoma, pancreatic endocrine tumor, parathyroid adenoma
- MEN1 (menin) - tumor suppressor, Chr 11

50

MEN2A

- MEDULLARY THYROID CARCINOMA (amyloid on bx, prophylactic thyroidectomy), pheochromocytoma, parathyroid hyperplasia (hypercalcemia)
- RET (RTK in cells of neural crest origin)

51

MEN2B

Medullary thyroid cancer, pheochromocytoma, MUCOSAL NEUROMAS, MARFINOID HABITUS
- RET (oncogene)