Endocrinology Flashcards

Question

B-Hcg tumors

Answer 1

Unique to boys In chest, pineal gland, gonad, or liver (heaptoblastoma) B-hcg crossreacts w/ Lh, binds too, enlarges testes slightly Stim Leydig cells and secreting androgens

Answer 2

Boys- no testic enlarge by 14, girls no breast by 13, no period by 14 Hypogoadotropic hypogonad inactive hypothal/pit, low FSH/LH, low test/estriol, flat stim test Hypergonadotropic gonadism- end-organ dysfn, FSH/LH HIGH, low test/estriol (hypothal/pit are fine)

Answer 3

Constitutional delay of puberty more common in boys, often fam hx, often w/ delay of growth too Chronic disease- IBD, arex, renal fil, heart failure Hypopit- brain tumors Primary hypothyroid Prolactinoma Genetic- Kallman (no gonadotropin or smell), Prader-Willi, Lawrence-Moon-Biedl (obesity, retinitis pigmentosa, hypogonad, polysyndactyly)

Answer 4

Chromosomal disorers- XXY klinefelter in boy, in girl thing turner/gonadal dysgen Autoimmune like hashimotos thyroid or addison's disease Eval w/ cbc, esr, t4, testosterone, estradiol, fsh, lh, prolactin, bone age

Answer 5

First 7 week s= undiff gonadal tissue, male sex diff = active, female = absent

Answer 6

SRY gene on short arm of Y chromo, by 9 weeks diff gonads into fetal testes, makes testosterone + AMH Internal ducts- test from fetal Leydig cells => development of wolffian ducts (epididymis, vas def, seminal vesicles0 and AMH from sertoli - inhib mullerian development External genitalia- conversion of testoerone to DHT by 5a reductase in skin of external genitalia. DHT = penile enlargement, scrotal fusion + masculinization of external Genitalia (complete at 12 weeks, then penis keeps growing)

Answer 7

W/out SRY, gonads become ovaries Internal ducts- not testicular tissue, no AMH, so wolffian ducts regress, development of mullerian vag 1/3, uterus, fallopian tubes External genitalia- do not virilize b/c no destosterone/DHT. so labia, clit, lower vag

Answer 8

1. Inborn testosterone synthesis error 2. Gonadal intersex- Mixed gonadal dysgen- 45XO 46XY mosaicism, ambigious genitalia, testis/vas defens one side = streak gonad on other, maybe fallopian tubes 3. True hermaphroditism- 46XX usually, but can be xy, have both ovary/testicular gonadal tissue 4. Partial androgen insensitivity- some peripheral androgen resistance, defective binding (testic feminization have total insensitivity, look like normal pheno females)

Answer 9

1. CAH from 21 ydroxylase deficiency = most common cause, 11-BOH and 3hDH also 2. Virilizing drug used by momma in prego 3. Virilizing tumor of momma in prego

Answer 10

Careful history of fam hx, maternal drugs etc P.e- gonads? swelling? bifid scrotum, labial fusion, urogen sinus, hypospadias? Increased BP suggests CAH w/ 11BOH deficiency Decreased BP suggests adrenal insufficiency Chromo studies Radiograph pelvic u/s genitogram Lab studies- mal DHT/testosterone..if test low, inborn error of anrogen synth maybe? female pseduoherm- serum electro, testost, CAH looking MGMT- focus on gender assignment asap, uroglogy, hormonal

Answer 11

Cortex makes lots of steroids Medulla makes catecholamines Major pathways - mineralocorticoids, glucocorts and androgens Glucocort/androgen synth regulated by neg fb loop via ACTH, but mineralocort = RAAS, indep of it/ACTH

Answer 12

Destroeyd cortex or enzyme deficiency Signs of cortisol def (arex, weak, hyponat, hypotn, increased pigment over scars) + aldo deficiency (FTT, salt craving, hyponat, hyperK) Addion's disease, CAH, adrenoleukodystrophy (x-linked recessive

Answer 13

Any process interfering with CRH in hypothal or ACTH from pit (prob at hypothal or pit level) Serum potassium may be normal b/ cno aldo deficiency Examples = pit tumors, carnipharyngioma, langerhands cell histiocytosis. Most common = iatrogenic, after long term glucocort dose

Answer 14

Enzyme def => underprod of cortisol/aldo + build-up precursors shunt into another path +> more ndrogens 21 Hydroxylase = 90%, three options. 1. Classic salt wasting- girls w/ ambig genitalia, 1-2 weeks boys + girls = FTT, vom, electrolytes eird (cortisol and aldo down) 2. Simple virilizing CAH = only glucocorticoid path is affected => only cortisol def, so ambig genitalia for girls, boys present a 1-4 years w/ tall stature, advancing bone age, pubic hair, penile enlargement 3. Nonclassic CAH- late onset w/ very mild cortisol def, no mineralocorticoid. At 4-5 yo, girls w/ premature adrenarche, clitoromeg, acne, rapid growth, hirsut, infert. Boys = premature adrenarche, rapid growth, premie acne 11B hydroxylase- 5% hypertensive hypokal 3b DHD- salt-wasting crises, glucocorticoid def, ambig genitalia (early block in all three paths)

Answer 15

21hydroxylase def = increased 17 hydroxyprog 17 OHP 11bhydrox def= increased levels of 11-deoxy specific compound S 3B hydroxysteroid DH def = increased DHEA and 17 hydroxypregnelone

Answer 16

Give cortisone to suppress ACTH production so androgen production down but not interfering w/ proper growth If aldo deficient, mineralocorticoid replacement (fluorocortisol), to normalize plasma renin activity F/u essential and growth velocity, physical exam, bone age, lab test monitored carefully, compliance super impt, need stress dose steroids sometimes

Answer 17

Why? chornic supraphysio steroid use, or Addisons disease from Ai destruction of adrenal cortex maybe w/ hashimoto's thyroiditis, T1DM (type I polygland syndrome), or hypoparathy/mucocandidiasis (type II polygland) Or b/c acute adrenal hemorrhage in neonate/septicemia, or Waterhouse-Friderichsen syndrome

Answer 18

High index of suspicison, look a hx of AI or prior steroid use, do ACTH stim tst (measure adrenal cortisol reserve). If blunted response, indicates primary renal insuff. Compare baseline cortisol to 1 hour after. Random cortisol level not hlepful, but >20 ug/dl in stress excludes AI Mgmt- Adrenal crisis = EMERGENCY, prompt IVF + 5% dextrose in normal saline + hyponat/prevent hypoglycemia Give steroids till stabilized

Answer 19

Clin- poor growth w/ delayed bone age, central obesity, moon facies, nuchal fad pad, easy bruising, purplish striae, HTN, glucose intol Why? Iatrogenic from chronic steroid use for asthma/IBG/JRA, or Cushing from benign/malig adrenal tumors, or Cushings disease = ACTH prod by pit tumor Lab eval- elevated free cortisol in 24 hr urine, absence of expected cortisol suppression in dex supp test. Cortisol excess can be confused w/ OBESITY. But obesity = fast growth + advanced bone age

Answer 20

Why? Genetic factors, n pattern, 95% HLA haplotypes DR3/4, monozygotics w/ 50% concord, dizyg 30%, _ viral infections maybe (enterovirus and rubella), early intro of cows milk? AImmune- islet antibodies in 85% pts, ICA in asx pts 10 years before sx, also antibodies against insulin + against glutamic acid GAD, up to 10% pop may have ICA..so nee a combo of factors

Answer 21

Clin fx- polyuria/dip/nocturia, enuresis, then wl/vom/dehy DKA can be initla pres in 25%, younger pts go more quickly to DKA Girls w/ monilial vulvovaginitis, adolescents may present in puberty w/ hormones antagonistic to insulin (GH and sex steroids) Dx- hyperglycemia w/ random bs above 200 + polyur/dip/wl/ornocturia

Answer 22

Insulin- short acting, int, long, very long Combo the insulins, or use insulin pup Monitor- Daily blood glucose before meals + at bedtime Hgb1Ac- check every 3 months Wtch for hypogly, have glucagon on hand Honeymoon period- after initial dx, 75% patients have temp progressive reduction in insulin reqs b/c transient recovery of islet cells => insulin, but only lasts up to 1-2 years Diet- follow ADA diet, edu/close follow up Long term- Microvasc, macrovasc in adulthood, DKA when ill

Answer 23

evening dose of insulin too high, hypoglycemia in early morning, then epinephrine and glucagon come out..so then high BG/ketones in mroning tx = lower bedtime insulin dose

Answer 24

2-3% of all kids with diabetes, 10x increase b/c of obesity. insulin resistance VERY strong herediatry comp, peripheral tissue resistance to insulin + decline in insulin secretion Clin fx- Asx to mild DKKA (less common), obesity, aanthosis nigricans MGMT with oral hypoglycemic agents if moderate, insulin if high blood sugar

Answer 25

Hypergly > 300 mg/dl with ketonuria + serum bicarb < 7.3 Pathophys = insulin deficiency, diminished glucose substrate at cellular level, body make more glucose, hypergly -> osmotic diuresis, and counter reg stress hormones released (glucagon, epi, cortisol, Gh)... glucagon => free fatty acids convert into ketone bodies (acetone, acetoacetae, b hydroxybutyrate), lipolysis = DKA

Answer 26

Present w/ vom/poly/dip/dehydration for MILD, Severe= severe dehydration, ab pain (like appendicits), rapid and deep respirations (Kussmaul), coma. Fruity breath Lab = AGMA, hypergly/glucosurine, ketonemia/ketonuria, hyperkal from mets acid (moves out of cells) MGMT = fluid/electrolytes w/ isotonic saline, gradually decline osmolality (minimze cerebral edema risk), K repletion w/ K acetate/phosphate serum might be normal but cells arent. K phosph => increased 2,3, DPG, shifts o2 dissociation to R, more available for tissues Regular insulin - continuous infusion Goal- stop hepatic glucose, reverse ketogen, shut down release of counter-reg hormones, enhance peripheral uptake Compx- cereral edema 6-12 hours or 24 hours rarely, if younger than 5 pt, faster than 100 mg/dl drop in glucose, or more than 4L /m2 /24 hours, 70% death, also severe hypoK and hypocalc

Answer 27

HPT regu by feedback between t3, t4, TRH and TSH T4/t3 bind TBPs like TBG and TBPA unbound = biologically active

Answer 28

Subotimal growth, goiter, myxedema/puffy/orange skin, amenn/oligomenn

Answer 29

Most common mets disorder, 1 in 4K Why? Thyroid dysgen = most common- 2/3 w/ absent thy gland, 1/3 ectopic anywhere from tongue to chest Thyroid dyshormonogen- inborn errors of hormone synth, present recessive w/ goiter. Pendred = organification defect, has sensorineural hearing loss PTU in pregnancy -> transient hypothy in newborn Maternal autoimmune can => transient b/c antibodies cross placenta

Answer 30

Asx at birth, unremarkable, but over 2 years 1. prolonged jaundice, poor feeding, lehargy, constipation large anterior/post fontanelles, protruding tongue, umbilical hernia, myxedema/mottled skin, hypotherm, elayed neuro, poor growth MGMT- immediately give l-thyroxine! dont delay till symptoms appear bc neuro sequelae :( Dx- neonatal screening measure TSH, increased TSh = first sign of failure, low t4, or antithyroid antiboides (TAPAB)

Answer 31

Most common cause of acquired hypothyroid, more in girls Etio- thyroid autoabs, thyroid cell cytotox Clin fx- asx, goiter, short stature, transient hyperthy (Hashitoxicosis) MGMT- l-thyroxine

Answer 32

Lid lag exophthalmos Thyroid enlarged/smooth Tachy/palpiations/warm flushed skin Vitiligo/alopecia = maybe autoimmune polyendo (Addisons/DM) CNS shows nervousness and fine tremors w/ hx of fatigue/school concentration Pubertal- delayed menarche/gynecomastia in boys

Answer 33

Diffuse toxic goiter, autonomous production of excessive hormone by gland b/c of TSH-like stim ab Most common cause of hyperthy in childhood, more females Why? strong genetics, TSI (IgG), see increased t3/t4 with supressed TSH MGMT = atithryoid PTU and methimazole. Both inhib synth, and PTU also stops periph t4=>t3 convert, first-line Subtotal thyroidectomy if antithy fails, or radioactive iodine if med compliance issue

Answer 34

Vit D/PTH release ca and phosph from bone PTH maintains normal ca level by releasing calcium from bone/resorbing ca from kids PTH releases phosph from bone and excretes from kids K1a hydroxylase vit D made in kidney, converts 25 oh vit D into active 1,25 OH vit D (stim by PTH) GI - ca absorbed in intestine due to 125OH vit D

Answer 35

less than 8.0 mg, or ionized less than 2.5 Pseudohypo if look slow b/c serum albumin low..so check ionized Fx- tetany, carpopedal spasm (ankles/wrsts, periph motor nerves too excitable0, laryngospasm, paresthesia, seizures in younger kids

Answer 36

Early neonatal = transient, maybe w/ premature/IUGR/asphyxia/infants of DM mothers, or hypomag => hypocalc Late neonatal > 4 days = 1. HypoPTH- low calc, elevated phopsh, from asx maternal hyperPTH, mom's high ca crosses plac, suppresses PTH 2. Di George 3. Hyperphophatemia => hypocalc b/c binds to calcium from uremia or too much formula Childhood hypoca 1) PTH Failure (genetic/digeorge) 2. PseudohypoPTH- rare dom disorder w/ PTH resistance, short stature, developmental delay, high PTH 3) hypomag- low mag => low ca b/c interferes w/ PTH 4) Vit D def => hypocalc w/ low phosph

Answer 37

Lab eval- serum ionized ca, phosph, mag EKG w/ prolonged QT found in hypocalcemia PTH level to see hypopth vs. pseduo, vit d level, look for rickets MGMT- milkd asx no tx, if <8, correct to avoid CNS hyperexcitability Ca supp- oral therapy if no seziures, IV calc gluc if pts sx, 1,25 vit D calitriol if chronic hypoPTH

Answer 38

Vit D def => down bone mineralization, normal bone matrix Why? exclusively breastfed with no sunshine, fad diets, anticonvulsants (phenytoin/phenobarb), interfere w/ liver mets, renal/hep failure How? Vit D def, GI disorders w/ malabsorb, nutritional, Defective Mets from renal/hep fail => renal osteodystropy Fx- first 2 years or in adolescence (rapid growth phase), wrists, knees, ribs, knobby, bowed, short, rachitic rosary (costochondral junctios prominent), craniotabes (pingpong ball skull?), bossing, delayed suture closue X-ray shows end of metaphysis cuppedfrayed, widened, Lab= low serum phosph, low/normal serum ca, elevated alk phosph, elevated PTH

Answer 39

VERY RARE, autosomal recessive enzyme def in kidneys of 1ahydroxylas, no 1,25 oh vit D Increased PTH, low vit D levels, low ca, low phopsh, up alk phosph

Answer 40

Familial hypophophatemia Most comon form, X-linked dom disorder Renal tubular phsophorus leak, low serumphosph level Rickets w/ normal calcium + low phopshorus Bowed legs but no tetany

Answer 41

Phsophate-deficient form w/ bone/soft tissue tumor, consider if bone pain/myopathy

Answer 42

Can't concentrate urine b/ low ADH or kidneys not responding ADH increases permeability of renal collecting ducts to water to water Central = ADH deficient, b/c of Autoimmune, trauma, hypothal tumors (craniophar, glioma, germinoma), langerhans histiocytosis, granulomatous disease, vasc, genetic Nephrogenic = x-linked recessive Fx- nocturia, enuresis, poor weight gain, polydip, polyu Eval/Dx- if thirst working and kid drinking, electroytes normal, otherwise hypernatremic dehydration w/ inappropriately dilute urine..up serum osmolality Early morning urine specimen w/ SG > 1/018 r/o DI Water deprivation test in hospital- rising serum osmolality and low urine! MRI of head, bone scan for Langerhands, MGMT = DDAVP

Answer 43

Less than 40, whole blood less than 45 Recog early in babies b/c brain needs it! Newborns/ infants = lethargy, myoclonic jersk, cyanosis, apnea, seizures Older = like adults, tachy, diaphor, tremors, h/a, seziures

Answer 44

Transient @ screening for high risk infants- preemie, asphyxia, SGA, fetal distress, LGA Inappropriate hyperinsulinism in SGA/diabetes mothers Persistent = hypogly for mroe than 3 days- 1. hyperinsulin from nesidioblastosis (islet hyperplasia) or beckwith-wiedemann- vmegaly of things 2. hereditary defects in carb mets (galactosemia/glycogen storage) AA mets issues 3. hormone deficienes- gGH/cortisol deficiency Congen hypopit if neonate w/ hypogly, microphallus = midline defects

Answer 45

Uncommon in older kids, ddx 1. Ketotic hypogly- late in morning in presence of ketonuria + low insulin level, can't adapt to fasting state, kids are thing and hypoglycemic after infection 2. Ingestion of alcohol (deplete cofactors for gluconeo), oral hypoglycemic 3. IEM 4. Hyperinsulinism