Precocious Puberty

Question 1

How to GnrH stimulation Test

Answer 1

Baseline LH then 100 mcg IV GnRH or 20mcg/kg leuprolide acetate then repeat LH after 30-40 minutes

N: 3.5-5 IU/L

Question 2

Goals of tx

Answer 2

to stop or slow development until normal pubertal age
to maximize adult height
to reduce the risk of psychosocial problems associated with early sexual maturation.

Question 3

Baseline Tests

Answer 3

• X-ray of left hand and wrist (bone age)
• Pelvic UTZ may reveal functional ovarian cyst
• Basal LH, FSH
• TSH, FT4 r/o hypothyroidism
• MRI (rule out brain lesion)
• GnRH Stimulation Test

Question 4

GnRH Stim Test normal add the ff tests

Answer 4

• Estradiol
• Testosterone
• HCG (ovarian tumor)
• Late afternoon cortisol (cushing)
• DHEAS (as in adrenarche)
• 17-OHP (CAH)

Question 5

When to treat

Answer 5

1) progress to next stage in 3-6 months
2) growth velocity >6cm/yr
3) bone age advanced >1 yr
4) predicted adult height below target range or decreasing

Question 6

How/what to monitor

Answer 6

q3-6 months
Stim LH
Bone Age
Tanner
Growth velocity

Question 7

Therapeutics for Central PP

Answer 7

Leuprolide 3.75-7.5 mg q1 or 11.25 mg q3months
Triptorelin 3-3.75 mg q1 or 11.25 q3
Goserelin 3.6 mg q1or 9.8mg q3
Buserelin 6.3mg q2
Histrelin 50mg implant yearly

Q3-6 months test for stimulated LH 30-60mins after and should be <3 IU/L

Question 8

most common tumor for peripheral PP

Answer 8

functional ovarian follicular cyst

Question 9

most common tumor central PP

Answer 9

hamartoma

Question 10

MOA of McCune Albright Syndrome

Answer 10

caused by a somatic mutation of alpha subunit of G-protein encoded by GNAS1 gene  causes activation of adenylate cyclase  continuous stimulation of endocrine function

Question 11

Triad of McCune Albright

Answer 11

Polyostotic fibrous dysplasia of the bone + PP + café au lait spots

Question 12

Differentials Central PP

Answer 12

Idiopathic (90%)
Tumors (hamartoma, astrocytoma, pineal tumor, optic or hypothalamic gliomas)
trauma
KISS1R defects
severe primary hypothyroidism
CAH

Question 13

Differentials Peripheral PP

Answer 13

McCune Albright syndrome, CAH
Gonadal tumor (functional follicular cysts – most common)
Adrenal tumor
Endocrine Disruptors or xenoestrogens  mimic estrogens (polychlorinated biphenyls, herbicides, pesticides, plasticizers (BPA?)