Endocrinology

Question 1

solitary maxillary central incisor indicates high likelihood of __ deficiency

Answer 1

GH deficiency

Question 2

Prolactin is (low/high) in hypothyroidism

Answer 2

HIGH because TRH is increased which inhibits production of DA from hypothalamus

Question 3

Constitutional growth delay:

growth velocity?

bone age?

fam hx?

Answer 3

NORMAL growth velocity

DELAYED bone age

+ Fam Hx of delayed puberty

Question 4

Diagnosis of DI

Answer 4

Clinical: polyuria, polydipsia, chronic dehydration

Urine: pale, colorless, Osm <300, SG <1.010

Dx via water deprivation test of giving DDAVP

Question 5

SIADH:

serum NA?

serum Osm?

urine Osm?

urine volume?

ADH?

atrial natriuretic peptide?

Answer 5

HYPOnatremia

LOW serum Osm

HIGH urine Osm

LOW urine output

HIGH serum ADH

NORMAL atrial nat peptide

Question 6

What causes SIADH?

Answer 6

pna,t umor, TB, CF, meningtiis, head trauma

Question 7

What causes hyponatremia in ICU setting?

Answer 7

SIADH vs cerebral salt wasting (caused by CNS disorders such as tumor, CVA, head trauma, hydrocephalus)

Question 8

What will you see with cerebral salt wasting?

serum NA?

serum Osm?

urine Osm?

urine volume?

ADH?

atrial natriuretic peptide?

Answer 8

HYPOnatremia

LOW serum Osm with HYPOvolemia

HIGH urinary Na excretion

INCREASED urine output

LOW vasopressin

HIGH atrial peptide

Question 9

what causes cerebral salt wasting?

what is treatment?

Answer 9

hypersecretion of atrial natriuretic peptide

Replacement of urine output with IV fluids (NS to 3% saline)

Question 10

What is inheritance pattern of these disorders that cause tall stature?

1. Klinefelter syndrome
2. Marfan’s
3. homocystinuria

Answer 10

1. XXY
2. AD
3. AR

Question 11

Marfan syndrome has (up/down) lens subluxation and (up/down) IQ.

Answer 11

Marfan: UP/UP

Homocystinuria: Down/Down

Question 12

What is Sotos syndrome (aka cerebral gigantism)

Answer 12

• Infants born >90th% and grow rapidly in 1st year of life to >97th%
• Growth continues for 4-5yrs, then returns to normal rate
• children have big hands/feet and are clumsy
• most end up with normal height
• GH levels are NORMAL! (this is NOT an endocrine d/o)

Question 13

How would an adolescent female present with prolactinoma?

Answer 13

• HA
• Amenorrhea
• galactorrhea (milk from breasts)
• visual-field defects
• Usually presents after puberty

Question 14

What is Beckwith-Wiedemann syndrome?

Answer 14

• fetal overgrowth with organ hypertrophy
• macroglossia, HSM, nephromegaly
• pancreatic B-cell hyperplasia (hypoglycemia)

**predisposed to WIlms tumor, adrenocortical carcinoma, and hepatoblastoma

• need to follow with abd U/S every 3mo until age 8 and AFP every 6wks until age 6

Question 15

What hormone is reponsible for initiation of puberty?

Answer 15

GnRH

Question 16

What is initial sign of puberty in girls?

How long before menarche begins?

Answer 16

Breast development (usually by 10-11yo)

Menarche occurs about 2-2.5yr later; which is breast Tanner stage 4

Question 17

When is peak height velocity in girls?

When does growth spurt occur in boys?

Answer 17

Girl: breast stage 2-3 (bt 11-12yrs) and ALWAYS before menarche…they will continue to growh about 3 more inches after menarche

Boy: During genital states 4-5 (bt 13-14yo)

Question 18

First signs of puberty for boys?

Normal age for male puberty to begin? Female?

Answer 18

Testicular growth and scrotal thinning…then penis lengthening….then pubic hair

Normal male age: bt 9-14yo

Normal girl age: bt 6-8yo

Question 19

Def of precocious puberty?

How to diagnose precocious puberty?

Answer 19

Def: onset of 2ndary sexual characteristics before 8yo in female and before 9yo in males

Dx: measure LH during sleep bc it is pulsatile (will be detectable in 50-70% in precocious girls and boys)

Measuring GnRH is boys is helpful…will see LH>FSH response in early stages

Question 20

What is most common brain lesion to cause precocious puberty?

Answer 20

Hypothalamic hamartoma (ectopic neural tissue that contains GnRH secretory neurons)

surgical intervention not recommended, except for those with intractable sz

Question 21

What syndrome has these clinical features?

Cafe-au-lait spots with jagged “coase of Maine” borders that usually follow midline

Polyostotic fibrous dysplasia (bone fractures)

Precocious puberty d/t autonomous endocrine hormone excess

Answer 21

McCune-Albright syndrome

Question 22

What is classic endocrine presentation of McCune-Albright in girls?

Answer 22

Vaginal bleeding

Question 23

What is premature thelarche

Answer 23

isolated breast development that occurs** before age 2**

usually benign condition; must r/o exogenous exposure to estrogen creams/shampoo/OCPs