Clinical_Rounds_in_Endocrinology_Volume_II_-_Pediatric_Endocrinology

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50. How to evaluate a girl with isosexual precocious puberty?

An approach to a girl child with precocious puberty is summarized in the algo-

rithm given below (Fig. 6.13).

51. What are the diagnostic cutoffs for basal and stimulated gonadotropins/estradiol
    for differentiating between GDPP and GIPP in a female child?
    In a girl presenting with precocious puberty, basal serum LH, estradiol, and LH
    response to GnRH should be performed. Basal LH ≥0.3 IU/L (ICMA) has a sen-
    sitivity and specificity of 35 % and 100 %, respectively, for the diagnosis of GDPP,
    and basal serum estradiol ≥10 pg/ml has a sensitivity and specificity of 39 % and
    100 %, respectively. Basal serum estradiol >100 pg/ml suggests a diagnosis of
    precocious puberty due to ovarian cyst/tumor. Various GnRH agonists (e.g., leu-
    prolide, triptorelin) have been used for the assessment of LH response to
    GnRH. Peak LH ≥5.0 IU/L at 60 or 120 min, after subcutaneous administration
    of aqueous leuprolide (20 μg/Kg) and/or serum estradiol ≥50 pg/ml at 24h, is
    suggestive of GDPP. Peak LH ≥8 IU/L at 3h after subcutaneous administration of
    aqueous triptorelin acetate (0.1 mg/m^2 , maximum of 0.1 mg) and/or serum estra-
    diol ≥80 pg/ml at 24h suggests a diagnosis of GDPP. However, it should be
    remembered that these cutoffs may not be applicable to children <3 years of age
    because of lack of cutoffs for defining precocity during mini-puberty in this age

Breast development ≥B2 < 8yrs or menarche <9 yrs

TSH

(Exclude primary hypothyroidism)

Basal and stimulated LH and E2

↓LH, ↑E2

MAS

GIPP

Exogenous Isolated

premature

thelarche

Isolated

premature

menarche

Ovarian

cyst/tumor

MR sellar

imaging

GDPP

↑LH,↑E2 ↓LH,↓E2

Fig. 6.13 Approach to a girl with precocious puberty

6 Precocious Puberty