Endocrinology

Question 1

What is Hypopituitism?

Answer 1

• Decreased production of anterior pituitary hormones
• Order of reduced production- GH, FSH&LH, TSH, ACTH, Prolactin
• Panhypopituitism- reduced production of all the pituitary hormones

Question 2

What are the causes of Hypopituitism?

Answer 2

1. Hypothalamus- Kallmans syndrome, tumour, inflammation, infection (Meningitis, TB) Ischaemia
2. Pituitary stalk- trauma, surgery, mass lesion
3. Pituitary- pituitary tumour, Inflammation, autoimmunity, infiltration- haemochromatosis amyloidosis mets, Ischaemia- sheehans syndrome (pituitary necrosis after PPH, pituitary apoplexy, DIC

Question 3

Clinical presentation of Hypopituitism

Answer 3

Mass symptoms: headache, visual field defects, Diplopia, CN IV-VI palsy,

GH deficiency- central obesity, reduced CO, Osteoporosis, reduce blood glucose, reduced muscle bulk and wellbeing

FSH& LH - women- Amenorrhoea/ Oligomenorrohea, vaginal dryness, dyspareunia, breast atrophy, lack of libido, infertility
Males- erectile dysfunction, reduced facial hair growth, lack of libido, reduced muscle bulk, decreased testicular volume, infertility

TSH- hypothyroidism sx- cold intolerance, weight gain, consultation, low mood, thinning of hair, loss of lateral 2/3 eyebrows, menorrhagia

ACTH- adrenal insufficiency- no hyperpigmentation,

Prolactin- usually not decreased but absent lactation

Question 4

Investigations for hypopituitism

Answer 4

Bloods- measure target hormones and pituitary
IGF-1, FSH, LH, oestrogen, progesterone, testosterone, TFTs, Cortisol, ACTH, Prolactin, dopamine, Glucose U&Es

Refer to endocrinology for Dynamic tests:
Short synacthen
Insulin tolerance test CI: epilepsy, heart disease and adrenal failure can do glucagon stimulation test instead normal GH>20 peak cortisol>550
Arginine and GHRH

Question 5

Management of hypopituitism

Answer 5

Hormone replacement therapy
Hydrocortisone for secondary adrenal failure prior to others
Thyroxine
Hypogonadism- HRT- oestrogen, progesterone, testosterone
Fertility- FSH& LH
GH- somatotrophin mimics GH

Treat underlying cause if tumour- surgery/ radiotherapy/ conservative

Question 6

How to classify pituitary tumours?

Answer 6

Size
Micro adenoma <1cm
Macro adenoma >1cm

Functionality- non functioning or functioning- secrete hormone

Histology
Chromophobe- 70% many are non secretory, some cause hypopituitism, half produce prolactin, few produce GH or ACTH, local pressure effect in up to 30%
Acidophil- 15% secrete GH or prolactin local pressure effect in 10%
Basophil- 15% secrete ACTH local pressure effect rare

Question 7

Symptoms of pituitary tumours

Answer 7

Mass effects- headache, visual field defects, Diplopia, Reduced visual acuity, CN III - VI palsy, DI
Prolactinoma- hyperprolactineamia- galactorrhoea, male/ female infertility, olgiomenorrhoea/ Amenorrhoea
GH secreting tumours- Acromegaly- large hands and feet (spade) , macroglossia, outward growth of jaw and head, widely space, sweaty coarse oily skin, flattened nose, voice change
Secrete TSH- Thyrotoxicosis- hyperthyroidism- heat intolerance, weight loss, anxiety, irritability, palpitations, oligo/Amenorrhoea, diarrhoea
Secrete ACTH- Cushing’s disease
Hypopituitism