Precocious Puberty + Premature thelarche/ adrenarche/ menarche

Question 1

Define precocious puberty

Answer 1

Development of secondary sexual characteristics before 8y in F and 9y in M

Question 2

What are the subtypes of precocious puberty?

Answer 2

1. Gonadotrophin dependent (‘central’, ‘true’): premature activation of the hypothalamic-pituitary-gonadal axis
   FSH + LH raised
2. Gonadotrophin independent (‘pseudo’, ‘false’)
   due to excess sex hormones
   FSH + LH low
3. Benign/ non-progressive

Question 3

What is the pattern of development in gonadotrophin dependent and independent precocious puberty?

Answer 3

Dependent: same as in normal puberty

Independent: does not follow pattern of normal puberty

Question 4

What is the aetiology of gonadotrophin DEPENDENT precocious puberty?

Answer 4

Idiopathic in 90% females

CNS tumour

Genetics

Question 5

What is the aetiology of gonadotrophin INDEPENDENT precocious puberty?

Answer 5

Females: Ovarian cysts + Ovarian tumours

Males: Leydig cell tumours, hCG secreting germ-cell tumors, familial male limited precocious puberty

Both: primary hypothyroidism, exogenous sex steroids, adrenal pathology (CAH), McCune Albright syndrome

Question 6

What triad characterises McCune Albright syndrome?

Answer 6

Peripheral precocious puberty
Irregular café-au-lait spots
Fibrous dysplasia of the bones

Question 7

What are the female breast changes in Tanner stages of puberty?

Answer 7

1. Prepubertal
2. Breast bud
3. Juvenile smooth contour
4. Areola/nipple project above breast
5. Same shape nipple and breast

Question 8

How is precocious puberty identified?

Answer 8

Tanner staging

Question 9

What is Tanner staging?

Answer 9

2 independent criteria:
the appearance of pubic hair in both sexes;
+
increase in testicular volume + penile size + length in males
OR
breast development in females

Question 10

What should be examined in precocious puberty?

Answer 10

Height, Weight + BMI: early accelerated growth in PP

Assess visual fields: CNS tumour

Examine for Cafe-au-lait spots: neurofibromatosis or McCune-Albright

Question 11

What is indicated by Testes in precocious puberty?

Answer 11

Bilateral enlargement = gonadotrophin release from intracranial lesion

Unilateral enlargement = gonadal tumour

Small testes = adrenal cause

Question 12

What investigations can be performed in precocious puberty?

Answer 12

Bloods: LH, FSH, Oestradiol +/or Testosterone
Bone age: Wrist X-ray

Brain MRI
Pelvic MRI: ovarian cysts/ tumour

Question 13

What is treatment for central precocious puberty?

Answer 13

GnRH agonist: results in initial transient stimulation of gonadotropin secretion from pituitary, followed by complete, but reversible suppression of pituitary-gonadal axis

Question 14

What test can distinguish central from peripheral precocious puberty?

Answer 14

Gonadotropin-releasing hormone (GnRH) stimulation test
Measure LH, FSH, Oestradiol +/or Testosterone
Administer GnRH/ analogue
Measure LH at 30-60 mins

Question 15

Define premature thelarche/adrenarche/menarche.

Answer 15

Early partial sexual development, often characterised by transient and minimal pubertal development in the absence of other stigmata of puberty.

Question 16

Define premature thelarche.

Answer 16

Isolated development of the breasts in infancy
Uni-/ bilateral enlargement
May occur physiologically between 6m- 2y.
Non-progressive + not a/w areolar development.

Question 17

Define isolated premature menarche.

Answer 17

Premature vaginal bleeding.

Question 18

Summarise the epidemiology of premature thelarche.

Answer 18

Relatively common in girls <2y of age.

Question 19

Summarise the epidemiology of isolated premature menarche.

Answer 19

Uncommon.

Question 20

What is the management for premature thelarche/adrenarch/menarche?

Answer 20

Referral to specialist paediatric endocrinologist.

Question 21

Name a GnRH agonist

Answer 21

Leuprolide

Question 22

Name an aromatase inhibitor

Answer 22

Letrozole