Non-functioning Pituitary Tumours

Question 1

Define non-functioning pituitary tumours.

Answer 1

Pituitary adenomas are the third most common intracranial neoplasms in adults, accounting for about 10% of all intracranial tumours. They are diagnosed when patients present with hormone hypersecretion, plus visual and neurological deficits and hypopituitarism as a result of mass effect.

Question 2

Explain the aetiology/risk factors of non-functioning pituitary tumours.

Answer 2

Multiple endocrine neoplasia type 1 (MEN-1)
Familial isolated pituitary adenomas (FIPA)
Carney complex (CNC)

Question 3

Summarise the epidemiology of non-functioning pituitary tumours.

Answer 3

Pituitary adenomas are the third most common intracranial neoplasms (behind meningiomas and astrocytomas), accounting for about 10% of all intracranial tumours in adults. There is no known sex or racial difference in prevalence. The prevalence of pituitary adenoma varies from 19 to 28 cases per 100,000, in the UK.

Question 4

Recognise the presenting symptoms of non-functioning pituitary tumours. Recognise the signs of non-functioning pituitary tumours on physical examination.

Answer 4

Headaches
Erectile dysfunction
Gynaecomastia
Amenorrhoea
Infertility
Loss of libido
Hot flushes
Fatigue
Nausea/vomiting
Bitemporal hemianopia

Question 5

Identify appropriate investigations for non-functioning pituitary tumours and interpret the results.

Answer 5

Prolactin
Insulin-like growth factor 1
LH, FSH
Testosterone/oestradiol
Thyroid-stimulating hormone, free thyroxine
Morning cortisol
ACTH stimulation test
Insulin tolerance test for cortisol
Basic metabolic panel
FBC
MRI pituitary with gadolinium enhancement
Contrast enhanced CT pituitary