Hypogonadism (male)

Question 1

def of male hypogonadism

Answer 1

decreased testosterone production or sperm production or both

Question 2

aetiology of male hypogonadism

Answer 2

primary hypogonadism
-gonadal dysgensis (Klinefelters/ undescended testes)
-gonadal damage (infection e.g. mumps, torsion, trauma, autoimmune, iatrogenic)
secondary hypogonadism
-pituitary/hypothalamic lesions
-GnRH  deficiency (Kallmans, idiopathic)
-hyperprolactinaemia
-rare syndromes (Prader-Willi syndrome)

Question 3

what does dysgensis mean

Answer 3

defective development of the gonads

Question 4

what would chromosomal analysis of klinefelters reveal

Answer 4

XXY

Question 5

what would chromosomal analysis of prader-willi reveal

Answer 5

loss of critical region on chromosome 15

causes obesity & short stature

Question 6

epi of male hypogonadism

Answer 6

primary accounts for 30-40% of male infertility
secondary accounts for 1-2% of male infertility

most common primary cause is klinefelters

Question 7

history of male hypogonadism

Answer 7

delayed puberty if onset is before puberty

• decreased libido
• impotence
• infertility

Question 8

examination of male hypogonadism

Answer 8

prepubertal hypogonadism
-signs of delayed puberty (high voice, lack of facial hair)
-gynaecomastia
-eunuchoid productions (arm span>height)
-features of underlying cause (undescended testes)
postpubertal hypogonadism
-decreased facial hair
-small testes
-gynaecomastia
-facial wrinkles
-features of underlying cause (visual field defects due to pituitary tumour)

Question 9

investigations in suspected male hypogonadism

Answer 9

primary: low testosterone, high LH & FSH due to negative feedback
secondary: low testosterone, low or inappropriately normal LH & FSH

determine level of defect

primary: karotype (klinefelters)
secondary: pituitary function tests (9am cortisol, TFTs, prolactin), MRI of hypothalamic pituitary area, smell tests for anosmia