Pituitary Flashcards
What causes the syndrome?
Hypercortisolism
Symptoms?
Central obesity Striations Skin thinning Facial rounding Proximal muscle weakening
Metabolic complications of Cushing’s syndrome
Diabetes mellitus
Dyslipidaemia
Metabolic bone disease
Hypertension
What is Cushing’s disease?
Cushing’s syndrome caused by ACTH secreting tumour in the pituitary
2 causes other than Cushing’s disease?
Autonomous adrenal cortisol overproduction
Ectopic ACTH secreting tumour - adenoma/hyperplasia/carcinoma (rare)
What is a cause of hypercortisolism that must be excluded?
Pregnancy
Developmental sign of Cushing’s syndrome in children?
Decreasing linear growth velocity with accompanying weight gain
More common in…
Women (4:1)
Almost complete anterior pituitary failure:
Slightly elevated prolactin Decreased GH Decreased cortisol response to hypoglycaemia Decreased testosterone Normal thyroxine
Test for PRL?
Lactation
Test for LH?
Testosterone/estradiol
Test for FSH?
Spermatogenesis/folliculogenesis
Test for TSH?
T4/T3
Test for GH?
IGF-1 and insulin tolerance test (ITT)
Test for ACTH?
Cortisol - (synacthen, ITT)
Why is prolactin high in a pituitary tumour?
Tumour decreases inhibitory secretion of dopamine on the pituitary lactotroph so more prolactin is released
Mass effect of pituitary tumour?
Visual field defect (tumour pressing on the optic chiasm)
Cause of acromegaly?
Overproduction of GH leading to stimulation of IGF-1
Causes of gynaecomastia?
Androgen deficiency: Klinefelter’s, Kallman’s
Testicular failure e.g. mumps
Liver disease
Testicular cancer e.g. seminoma secreting hCG
Ectopic tumour secretion
Hyperthyroidism
Haemodialysis
Drug causes of gynaecomastia?
Spirinolactone (most common) Cimetidine Digoxin Cannabis Finasteride Gonadorelin analogues e.g. Goserelin, Buserelin Oestrogens, anabolic steroids
What is Sheehan’s syndrome?
Global hypopituitarism due to ischaemia in the pituitary following childbirth
Symptoms of Sheehan’s syndrome?
Agalactorrhoea (lack of prolactin), amenorrhoea (lack of FSH and LH), cold intolerance and constipation (lack of thyroid hormones) and weight loss (lack of steroid hormones)
Pituitary adenoma often causes what?
Hypopituitarism with mass effect symptoms like headache and bilateral hemianopa
