Abnormal Female Puberty

Question 1

What are the factors that initiate hypothalamic activity?

Answer 1

1- changes in the levels of central inhibitory neurotransmitters (dopamine & endorphins)
2- decreased sensitivity to small amounts of E2 circulating that used to suppress GnRH production
3- increased production of Leptin (by fat cells)
4- onset of adrenal androgen activity

Question 2

What are the factors determining the age of puberty?

Answer 2

1- genetic sex
2- geographic factors: near equator
3- body weight & nutrition
4- exposure to light
5- general health & psychological factors
6- familial factors

Question 3

What are the stages of thelarche?

Answer 3

Under the effect of estrogen
Tanner staging
T1 -> preadolescent: elevation of papilla only
T2 -> breast bud as small mound enlargement of areolar diameter
T3 -> further enlargement & elevation of breast & areola
T4 -> projection of areola & papilla to from mound above level of breast
T5 -> mature stage

Question 4

What are the stages of Pubarche?

Answer 4

Under the effect of ACTH & androgens
T1 -> vellum over pubes
T2 -> sparse growth of long slightly pigmented downy hair
T3 -> darker coarser & more curled hair
T4 -> hair resembles adult type but in a smaller area
T5 -> hair spreads to medial surface of thighs

Question 5

What is the classification of precocious puberty?

Answer 5

ISOSEXUAL PRECOCIOUS PUBERTY (secondary sexual characters like genetic)
- True isosexual
- false isosexual

HETEROSEXUAL PRECOCIOUS PUBERTY
- false heterosexual

Question 6

What are the causes of true isosexual precocious puberty?

Answer 6

GnRH-dependent
1- idiopathic
2- CNS lesions: hemartoma, neurofibromatosis, hydrocephalus, cysts of 3rd ventricle, Silver-Russel syndrome
3- obesity
4- primary hypothyroidism -> increased TRH & TSH -> increases FSH

All of them cause advanced bone age except hypothyroidism will cause retarded bone age

Question 7

What are the causes of false isosexual precocious puberty?

Answer 7

GnRH independent (peripheral cause)
1- estrogen secreting ovarian tumors
2- estrogen secreting adrenal tumors
3- functioning ovarian cysts
4- McCune Albright Syndrome -> cafe-at-lait & bone cysts
5- Iatrogenic (oral/local estrogen therapy)

Question 8

What are the causes of heterosexual precocious puberty?

Answer 8

GnRH independent -> disagreement of sexual characters with genetic 46-XX

1- Supra-renal adenoma/carcinoma
2- ovarian tumors (androblastoma)
3- Congenital adrenal hyperplasia -> 21 hydroxalase deficiency
4- Cushing’s syndrome

Question 9

How is incomplete precocious puberty diagnosed?

Answer 9

Isolated events of puberty is accelerated without evidence of estrogen in effects or increased bone age

Question 10

How is precocious puberty diagnosed?

Answer 10

1- karyotype
2- Bone age study
3- GnRH challenge test
4- Serum androgens
5- Imaging studies

Question 11

How does the bone age study aid in the diagnosis of precocious puberty?

Answer 11

• normal bone age -> isolated PP
• retarded bone age -> hypothyroidism -> do TFT
• advanced bone age -> full true/false PP -> do GnRH challenge test

Question 12

What are the results of the GnRH challenge test?

Answer 12

Give Leuprolide acetate -> measure LH & FSH after 3 hours
- +ive FSH & LH response (> 5ml) -> GnRH dependent
- -ve FSH & LH response (<5ml) -> GnRH independent -> serum E2 in case of iso & serum androgens in case of hetero
- if only FSH responds -> hypothyroidism

Question 13

In cases of heterosexual PP, what do the results of serum androgens indicate?

Answer 13

• fasting 17OHP -> CAH
• testosterone -> androgen produced by ovaries
• DHEA-S -> androgen produced by adrenal glands