Endocrinology / Genitalia Flashcards
severe hypoglycemia, wandering nystagmus, and small penis size in neonate. What does he have?
hypopituitarism
Micropenis length in full term neonate
less than 2 to 2.5 cm
Causes of micropenis
- gonadotropin deficiency
- primary testicular dysfunction, such as with Klinefelter syndrome
- Partial androgen insensitivity syndrome (but usually more ambiguous genitalia)
Name syndrome associated with gonadotropin deficiency associated with anosmia or hyposmia, WITHOUT hypoglycemia
Kallmann syndrome
Syndrome where cryptorchidism and micropenis are common, but also Hypoglycemia due to poor intake, hypotonia, poor feeding, respiratory problems, and dysmorphic features
Prader-Willi
Adolescent girl has sudden onset nausea, vomiting, right lower abd /pelvic pain without fever and is hemodynamically stable. Can have dysuria/frequency. Top of your ddx: ___ and mode of dx: ____
Right ovarian twist
Pelvic ultrasound with doppler
What disease causes bilateral absence of the vas deference?
Cystic Fibrosis
Lab findings in hypoparathyroidism
HypoCa
High Phos (PTH causes phos excretion through kidney)
Normal/high Vit D 25-OH (PTH stimulates 1alpha-hydroxylase in kidney to form 1, 25 vit D
–> increase absorption of Ca in gut)
Lab findings in hypoparathyroidism
HypoCa
High Phos (PTH causes phos excretion through kidney)
Normal/high Vit D 25-OH (PTH stimulates 1alpha-hydroxylase in kidney to form 1, 25 vit D
–> increase absorption of Ca in gut)
In hypoparathyroidism, which type of vitamin D supplement do you need?
vit 1,25 D because PTH stimulates 1a-hydroxylase to turn vit D 25-OH to vit D 1,25 to absorb Ca in gut.
Name of syndrome with similar lab findings as hypoparathyroidism. What differentiates it?
Albright hereditary osteodystrophy
Distinction: short stature, obesity, rounded face, brachydactyly, mild cognitive impairment
Lab findings in vit D deficiency
Hypo Ca
low Phos (PTH is stimulated and makes kidneys excrete phos)
Definition of delayed puberty in girls
lack of breast development at age 13
Girl with turner syndrome has not started puberty at age 11-12, next step?
order gonatotropin levels (FSH/LH) –> in hypergonadotropic hypogonadism (primary ovarian failure), FSH and LH would be HIGH
Guidelines recommend starting estradiol for pubertal induction at age 11-12 years for Turner syndrome AFTER primary ovarian failure is confirmed
Mode of estradiol to be given in Turner syndrome
transdermal
Definition of primary amenorrhea
no menarche by age 15
“low-energy balance”
low ft4 with nl tsh
low bmi
low-normal fsh, lh
Addison Disease (primary adrenal insufficiency) lab findings
Decreased cortisol, aldosterone
High K, low cortisol
high ACTH (hyperpigmentation)
High renin (in response to low aldosterone)
Low sodium
Dehydration
Lab findings in secondary adrenal insufficiency (pituitary dysfunction)
low ACTH
low cortisol
NORMAL aldosterone (because RAAS is intact)
normal K
sodium can be low
No skin hyperpigmentation
Chronic mucocutanous candidiasis, hypoparathyroidism, primary adrenal insufficiency. Dx?
Autoimmune polyglandular syndrome type 1 (APS-1)
Tx of adrenal insufficiency
hydrocortisone
fludrocortisone if primary
First step of management in DKA
fluid bolus 10 ml/kg over 30-60 min to prevent cerebral edema
after fluids, THEN insulin
Criteria for constitutional delay
bone age < chronological age
Look at bone age and what his actual height is
Bone age in familial short stature
equal chronological age
Growth hormone deficiency finding in terms of height
low height velocity <5cm/year
Criteria for starting statin in children
ldl level persistently 160 mg/dL or higher despite dietary management.
Causes of precocious puberty
adrenal gland, gonads, a human chorionic gonadotropin (hCG)–secreting tumor (in males), exogenous exposure to sex steroid, and severe hypothyroidism
Most sensitive sign of HPA axis activation in central cause of precocious puberty
LH >0.3
In boys, testicular size >4ml
In girls, development of breast tissue
What does measurement of 17-hydroxyprogesterone attempt to diagnose/rule out
Congenital adrenal hyperplasia due to 21-hydroxylase deficiency
Growth pattern in growth hormone deficiency and lab to send
Delayed bone age
Low insulin-like growth factor-1
In a boy not growing and has intrapartum excessive hemorrhage, what should you think about?
Sheehan syndrome (necrosis of pituitary gland) or pituitary hemorrhage
how does acquired growth hormone deficiency present?
Slowing of linear growth at 6-12 mo, delayed bone age
midline defects
small penis, cryptorchidism (if gonadotropin deficiency is present)
Most common cause of congenital hypothyroidism
thyroid dysgenesis (lack of or incomplete development of thyroid gland and etopic thyroid tissue)
What happens with infant when mother has Graves disease?
maternal receptor-blocking antibodies can suppress infant thyroid gland, causing transient hypothyroidism
If infant’s newborn screen shows TSH >40, next step?
start levothyroxine 10-15 microgram/kg/day by age 2 wk immediately without waiting for confirmatory test result
How should levothyroxine be given?
on finger with small amount of breastmilk or formula or water
NOT through bottle (has affinity to plastic)
Male infant born with hypospadias, small penis, testes, 46,XY karyotype, high LH, testosterone and DHEA, dx?
partial androgen insensitivity syndrome (PAIS)
What is the process of normal sex differentiation?
Bipotential internal and external structures
SRY sex determining region) and other Y chromosome parts –> testes
Leydig cells secrete testosterone (testes)
Sertoli cells secrete anti-Mullerian hormone (AMH)
Testosterone STABILIZES wolffian ducts –> epididymis, vas deferens, seminal vesicles, ejaculatory ducts.
AMH –> regresion of Mullerian structures (uterus, fallopian tubes, cervix, upper vagina)
Testosterone —(5alpha-reductase)–> DHT
DHT virilizes external genitalia –> growth of phallus, fusion of labioscrotal folds, igration of urethra to normal position on penis
Next step in a person with type 2 DM, hyperglycemia, polyuria, no acidosis
insulin
NOT fluids
Signs and symptoms of hypercalcemia due to immobilization
wheelchair bound, pathologic fracture
appropriate PTH and PTHRH (low) in setting of hypercalcemia
Serology for Graves Disease
+ TSH receptor antibody
physical exam of congenital adrenal hyperplasia and karyotype
There are mullerian internal organs (uterus), 46,XX. But there is a penis, +/- fused labioscrotal fold without gonads within.
Excess 17a-hydroxyprogesterone is converted to DHEA –> testosterone (virilized female)
In 46,XY, they appear normal, however with salt wasting (hypoaldosteronism, low cortisol, high testosterone)
Management of phimosis
If not pathologic, do nothing, just keep penis clean
If pathologic, can do topical steroids
Paraphimosis: emergency
When should you be concerned of ovarian masses
cysts <6 cm
ones that do not self-resolve after 2-3 menstrual cycles
complicated cysts
Labial adhesion that is asymptomatic in <5 yo, what’s the management
observation
It is self limiting
If symptomatic, trial of topical estrogen cream
What age should cryptorchidism be corrected by?
12 mo
What is the normal penis size of a term newborn
2-2.5 cm
Definition of gynecomastia
> 0.5 cm diameter of fibroglandular mass
Benign: SMR 3-4; aromatization of androgen to estrogen
Length rules of thumb
Increases 50% by 1 yo
Doubles by 4 yo
Triples by 13 yo
After 2 yo, velocity is 5 cm/year until puberty
Weight growth rules of thumb
Doubles by 4 mo
Triples by 12 mo
Quadruples by 24 mo
After 2 yo, velocity is 5 lb/year until adolescence
Pain referred to jaw, thyroid tenderness, fever, usually after URI
subacute thyroiditis
Tx: NSAIDs. May develop transient hypothyroidism
Cause of neonatal thyrotoxicosis
Transplacental delivery of TSI antibodies from mother with Graves disease
Self limiting
Maternal Ab will degrade by 6 mo
May need methimazole or BB
Albright’s hereditary osteodystrophy
Resistance to TSH, LH/FSH, PTH
Causes hypocalcemia (pseudohypoparathyroidism)– causes bracydactyly
Heterotopic intramembranous subcutaneous calcifications
Rachitic rosary finding, dx?
Rickets
Enlargement of costochondral junction along anterolateral chest
Rickets (cause, lab findings)
Vit D deficiency
High PTH, low phos, low Ca (cannot compensate for low Ca)
Mutation in FGF23 signaling
hypophosphatemic rickets
Inability to renally absorb phos
Hypophosphatasia gene and lab finding
ALPL
low ALP
When can you start GnRH therapy for gender affirming transition?
Smr 2
