Endocrine - Sex Hormone Disorders

Question 1

Which sex hormone disorder?
High LH
Low Testosterone

Answer 1

Primary hypogonadism

DDx:

• Klinefelter
• Cryptorchidism
• acquired testicular defects (viral MUMPS orchitis, radiotherapy, and drugs)

Question 2

Which drugs cause primary hypogonadism with acquired testicular defect?

Answer 2

Ketoconazole (inhibits testosterone synthesis)

Spironolactone (inhibits androgen action)

Marijuana (increases oestrogen)

Chemo (inhibits spermatogenesis)

• cyclophosphamide
• chlorambucil
• cisplatin
• busulfin

Question 3

Which sex hormone disorder?
Low LH
Low Testosterone

Answer 3

Hypogonadotropic Hypogonadism

Acquired:

• severe illness
• opioids
• obesity
• hyperprolactinoma
• sellar mass lesion
• haemochromatosis

Congenital:

• Kallman’s Syndrome
• Congenital GnRH deficiency without anosmia
• Prader Willi Syndrome
• Laurence Moon Syndrome

Question 4

How does obesity cause sex hormone disorder?

Answer 4

Causes acquired hypogonadotropic hypogonadism due to decreased SHBG

Decreases serum concentration of SHBG and therefore total testosterone BUT doesn’t decrease the free testosterone concentration

Question 5

How does hyperprolactinoma cause sex hormone disorder?

Answer 5

Causes acquired hypogonadotropic hypogonadism due to PRL inhibits GnRH secretion

Question 6

Which sex hormone disorder?
High LH
Normal/High Testosterone

Answer 6

Androgen Insensitivity Syndrome

Question 7

Inheritance of Androgen Insensitivity Syndrome?

Answer 7

X-linked recessive condition due to end-organ resistance to testosterone causing genotypically male children (46XY) to have a female phenotype

Complete androgen insensitivity = testicular feminisation syndrome

Question 8

Features of Androgen Insensitivity Syndrome

Answer 8

Primary amenorrhoea

Undescended testes causing groin swellings

Breast development may occur due to conversion of testosterone to oestradiol

Question 9

Diagnosis of Androgen Insensitivity Syndrome

Answer 9

High LH
Normal/High Testosterone

Chromosome analysis for 46XY genotype

Question 10

Management of androgen insensitivity syndrome

Answer 10

Counselling

Bilateral orchidectomy (increased risk of testicular cancer due to undescended testes)

Oestrogen therapy

Question 11

When do you MRI someone with low testosterone?

Answer 11

If <40yrs old with testosterone <250

If >65yrs with testosterone <150

Question 12

Steps to investigate secondary amenorrhoea?

Answer 12

1) Exclude pregnancy

2) Prolactin:
ELEVATED: hyperprolactinaemia (needs MRI)

3) TSH:
ABNORMAL: Rx and Dx thyroid

4) FSH:
INCREASED if decreased oestrogen = PRIMARY OVERIAN FAILURE

5) E2
LOW = Hypogonadotrophic hypogonadism
- functional hypothalamic amenorrhoea
- systemic illness (coeliac / T1 and T2 diabetes)
- other hypothalamic/pituitary causes

6) TESTOSTERONE:
ELEVATED = PCOS

Normal: need progestin withdrawal and progestin/oestrogen withdrawal –> if no bleeding then is ADHESIONS