Abnormal puberty Flashcards
What defines precocious puberty
Development of secondary sexual characteristics before:
- 8 years in females (more common)
- 9 years in males
What is thelarche, adrenarche and menarche
Thelarche = the first stage of breast development
Adrenarche = the first stage of pubic hair development
Menarche = onset of the first menstrual period
What are the types of (causes of) precocious puberty and what are the difference between them
Gonadotrophin dependent
- Premature activation of the hypothalamic-pituitary-gonadal axis
- FSH/LH raised
- Consonant sequence of development (normal)
Gonadotrophin independent
- Due to excess sex hormone production (NOT in pituitary gland)
- FSH/LH low
- Dissonant sequence of development (abnormal)
What are the causes of precocious puberty in girls
Usually idiopathic or familial and follows normal sequence of puberty
Gonadotrophin-dependent:
- Trauma, brain injury, hydrocephalus, irradiation, infection, tumours
- Cerebral palsy
- Pituitary adenoma
Gonadotrophin independent:
- Adrenal – Congenital adrenal hyperplasia, Cushing’s syndrome
- Tumours – b-hCG-secreting tumour of liver, tumours of ovary, testes, adrenals
- McCune-Albright syndrome
- Exogenous hormones – COCP, testosterone gels
- Ovarian – follicular cyst, granulosa cell tumour, Leydig cell tumour, gonadoblastoma
What is McCune-Albright syndrome, what are the clinical features and how is it treated
a multiple endocrinopathy of thyrotoxicosis, Cushing’s, acromegaly
S/S: polyostotic fibrous dysplasia, café-au-lait spots, ovarian cysts, precocious puberty
Mx: cyproterone acetate (antiandrogenic progestogen)
What investigations should be done for precocious puberty in girls
Bloods: LH/FSH, oestradiol, testosterone
Other: pelvic US, MRI brain, gonadotrophin stimulation test
What are the causes of precocious puberty in boys
Uncommon and usually has an organic cause (The testes are relatively insensitive to secretion of gonadotrophins from the pituitary gland)
Gonadotrophin-dependent:
- Trauma, brain injury, hydrocephalus, irradiation, infection, tumours
- Cerebral palsy
- Pituitary adenoma
Gonadotrophin independent:
- Adrenal – Congenital adrenal hyperplasia, Cushing’s syndrome
- Tumours – b-hCG-secreting tumour of liver, tumours of ovary, testes, adrenals
- McCune-Albright syndrome
- Exogenous hormones – COCP, testosterone gels
- Ovarian – Leydig cell tumour, testotoxicosis
What investigations should be done for precocious puberty in boys
Bedside: testicular exam
Other: MRI brain, gonadotrophin stimulation test
What does testes size on examination suggest for precocious puberty
Bilateral enlargement = gonadotrophin release from intracranial lesion
Unilateral enlargement = gonadal tumour
Small testes = adrenal cause (tumour or adrenal hyperplasia)
What is the management for precocious puberty
- Refer to paediatric endocrinologist
Detect and treat of any underlying pathology
Assess bone age and reduce rate of skeletal maturation if bone age is accelerating
Delaying puberty: Gonadotrophin-releasing hormone analogues e.g. leuprolide
Describe premature thelarche
Girls 6 months-2 years
Breast enlargement may be asymmetrical and fluctuate in size
Rarely progresses beyond stage 3 of puberty
Other features of puberty and accelerate growth is ABSENT (differentiates from gonadotrophin-dependent precocious puberty)
Investigations not required
Note: high maternal prolactin can cause newborn babies to be born with breast buds that may lactate → self-resolves in days
What are the causes of gynaecomastia
Klinefelter’s
Familial
Oestrogen-secreting tumours
Drugs - oestrogen, spironolactone, marijuana
What is premature adrenarche and what investigations should be done
sensitivity to androgen production by the adrenal gland from 6-8 years
USS- ovaries and uterus (girls risk of developing PCOS)
Bone age assessment
Urinary steroid profile- rule out CA Hot adrenal tumour
What defines delayed puberty
Absence of pubertal development by:
13 years in girls
14 years in boys (more common)
What are the causes of delayed puberty
Constitutional delay of growth and puberty/familial (most common in boys)
Low gonadotrophin (hypogonadotropic hypogonadism):
Systemic illness: CF, severe asthma, Crohn’s disease, organ dysfunction, anorexia nervosa, starvation, excess physical training
Hypothalamo-pituitary: pituitary dysfunction, gonadotrophin or GH deficiency, craniopharyngiomas, Kallman syndrome, Prader-Willi
High gonadotrophin (hypergonadotropic hypogonadism):
Chromosomal: Klinefelter’s, turner’s
Acquired: post-surgery, chemotherapy, radiotherapy, trauma, testicular torsion, autoimmune disorder
Androgen insensitivity syndrome
5a-reductase deficiency
