A 7 year old girl presents with premature breast development.
- What is the suspected clinical condition?
- Precocious puberty
- What are the main causes?
- Central precocious puberty (gonadotrophin dependent)
- Idiopathic
- CNS pathologies
- Hypothalamus hamartoma
- Pituitary adenoma
- Craniopharyngioma
- Hydrocephalus
- Post infection Encephalitis
- CNS irradiation
- Pseudo precocious puberty (gonadotrophin independent)
- Ovarian causes
- Granulosa cell tumors
- Sertoli-Leydig cell tumors
- Functional ovarian cysts
- Adrenal causes
- CAH
- Cushing syndrome
- Exogenous sex hormones
- McCune Albright syndrome
- Long standing hypothyroidism
- Isolated variants
- Thelarche
- Pubarche
- What is the investigation of choice to confirm the diagnosis?
- GnRH stimulation test
- How would you interpret the results?
- GnRH stimulation test is the gold standard test to diagnose precocious puberty. It is performed by measuring FSH & LH levels sequentially after administering GnRH analogue 100 micg IV bolus (0/20/40 min)
- This test has been used in the diagnosis of central precocious puberty (CPP) and in the differentiation of CPP from other causes of precocious puberty
- In pre-pubertal children both LH & FSH 2 IU/L>
- In healthy pubertal children the LH response exceeds the FSH response
- In central precocious puberty, GnRH stimulation shows a pubertal response with LH predominance (LH:FSH ratio >1). Peak LH levels vary, depending on the specific assay used, but values of >8 iu/l are usually considered diagnostic of CPP
- In pseudo precocious puberty relatively flat gonadotrophin response is seen with pre-pubertal level FSH and LH
- In thelarche variant, the FSH response exceeds the LH response
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