Tutorial 6

Question 1

Q: A 44-year old mother of two children presents to her GP complaining of headaches, tiredness, oligomenorrhoea and occasional expression of milk from her breasts (galactorrhoea).

Her doctor estimates her visual fields and concludes that there is some loss in peripheral vision. He takes a blood sample for laboratory analysis, the results of which are given below.

Oestradiol, <70 pmol/L, Low

Progesterone, <1.0 nmol/L, Low

Luteinising hormone (LH), 0.5 U/L, Low

Follicle stimulating hormone (FSH), 0.8 U/L, Low

Prolactin, 36,000 mU/L, Very high

A proper examination of the patient’s visual fields by perimetry confirmed a bitemporal hemianopia.

What is the diagnosis?

Answer 1

A: pituitary adenoma- prolactinoma (since high prolactin levels)- functioning tumour since still producing hormone

Question 2

Q: How is visual field affected by a pituitary adenoma? Why? How would this present?

Answer 2

A: loss of half vision= bitemporal (peripheral is lost)

pituitary is quite close to opitcal chiasm- peripheral vision is sensed by fibres in inner corner of retina

patient bumping into things

Question 3

Q: How can a pituitary adenoma affect oestrodiol levels?

Answer 3

A: low

ovaries aren’t making it (hypogonadism)

pituitary usually makes FSH and LH which stimulate ovaries but low levels of them

Question 4

Q: How can a pituitary adenoma affect FSH and LH levels?

Answer 4

A: can decrease

Question 5

Q: What is primary hypogonadism? secondary?

Answer 5

A: problem with ovaries

problem with pituitary

Question 6

Q: What are the principal characteristic features of an initial history that is consistent with ‘pituitary adenoma’? (3)

Answer 6

A: galactorrhea

infrequent menstrual cycles- prolactin inhibits FSH and LH

headaches- prolactin levels correlate to size of tumour

Question 7

Q: What is the relevance of the bitemporal hemianopia in terms of tumour identification?

Answer 7

A: shows that tumour is pituitary (prolactinoma) and that it’s pressing on the optic chiasm