Endocrinology Flashcards
(110 cards)
What is precocious puberty defined as?
Girls = breast development age <8yo
Boys = testicular development >4mL, age <9yo
What staging system is used for female breast development>
Tanner’s 5 breast development stages
What staging system is used for males testicular development?
Prader’s orchidometer
thelarche
breast development
Causes of precocious puberty
Gonadotrophin-Dependant Precocious Puberty [GDPP]
Gonadotrophin-Independent Precocious Puberty [GIPP] – 20% of PP
Benign isolated precocious puberty – these are all generally self-limiting
What causes gonadotrophin-dependent precocious puberty (GDPP)? Give examples
Premature activation of HPG axis
Idiopathic (no cause found in 80% girls and 40% boys)
CNS abnormalities (tumours, trauma, central congenital disorders
What causes gonadotrophin-independent precocious puberty (GIPP)? Give examples
Early puberty from increased gonadal activation independent of HPG
Ovarian – follicular cyst, granulosa cell tumour, Leydig cell tumour, gonadoblastoma
Testicular – Leydig cell tumour, testotoxicosis (defective LH-R function; a familial GIPP)
Adrenal – CAH, Cushing’s syndrome
Tumours – b-hCG-secreting tumour of liver, tumours of ovary, testes, adrenals
McCune-Albright syndrome – a multiple endocrinopathy of thyrotoxicosis, Cushing’s, acromegaly
S/S: polyostotic fibrous dysplasia, café-au-lait spots, ovarian cysts
Exogenous hormones – COCP, testosterone gels
CNS abnormalities that can cause Gonadotrophin-Dependant Precocious Puberty [GDPP]
tumours, trauma, central congenital disorders
Most common cause of Gonadotrophin-Dependant Precocious Puberty [GDPP]
Idiopathic (no cause found in 80% girls and 40% boys)
Ovarian abnormalities that can Gonadotrophin-Independent Precocious Puberty [GIPP]
follicular cyst, granulosa cell tumour, Leydig cell tumour, gonadoblastoma
Testicular abnormalities that can cause Gonadotrophin-Independent Precocious Puberty [GIPP]
Leydig cell tumour, testotoxicosis (defective LH-R function; a familial GIPP)
Adrenal causes of Gonadotrophin-Independent Precocious Puberty [GIPP]
CAH, Cushing’s syndrome
Tumours that can cause Gonadotrophin-Independent Precocious Puberty [GIPP]
b-hCG-secreting tumour of liver, tumours of ovary, testes, adrenals
What is McCune-albright syndrome? What can it cause?
a multiple endocrinopathy of thyrotoxicosis, Cushing’s, acromegaly
Gonadotrophin-Independent Precocious Puberty [GIPP]
Signs + Sx of McCune Albright Syndrome
polyostotic fibrous dysplasia, café-au-lait spots, ovarian cysts
NOTE: Cause of Gonadotrophin-Independent Precocious Puberty [GIPP]
Causes of benign isolated precocious puberty
Premature thelarche [isolated breast development before 8yo; normally between 6m and 2yo
Premature pubarche/adrenarche [isolated pubic hair development before 8yo (girls) or 9yo (boys)]:
Premature menarche [isolated vaginal bleeding before 8yo]
Investigations for precocious puberty
GnRH stimulation test (Gold Standard)
FSH, LH low = GIPP
FSH, LH high = GDPP
Wrist XR (non-dominant) for skeletal age
General hormone profile basal LH/FSH, serum testosterone and oestrogen
Urinary 17-OH progesterone if CAH suspected
Gold standard investigation for precocious puberty
GnRH stimulation test (Gold Standard)
FSH, LH low = GIPP
FSH, LH high = GDPP
What investigation done if CAH suspected?
Urinary 17-OH progesterone if CAH suspected
What additional investigation may be done in precocious puberty in females?
Pelvic USS
Which gender usually has an organic cause for precocious puberty?
Males - most likely has an organic cause
Females - not normally of concern
What additional investigation would be done in a male with precocious puberty?
Prader’s orchidometer measurement and examination of testes
Findings on testicular examination in someone with precocious puberty
Bilateral enlargement → GDPP (intracranial lesion –> MRI)
Unilateral enlargement→ gonadal tumour
Small testes → tumour or CAH (adrenal cause)
Bilateral testicular enlargement and precocious puberty
Bilateral enlargement → GDPP (intracranial lesion –> MRI)