Pituitary Tumours (non-fucntional)

Question 1

Definition of pituitary tumours (non-functional)

Answer 1

Almost always benign adenomas that are a common type of intracranial neoplasm/tumour.
• They can be considered:
• Clinically non-functional pituitary adenomas (CNFPAs) (NO hormone hypersecretion)
• Functional pituitary adenomas (Acromegaly, Cushing’s syndrome, prolactinoma)

Question 2

Aetiology and Pathophysiology of non functional pituitary tumours

Answer 2

• Unknown aetiology

• Can be classed as a Microadenoma (<1cm) or Macroadenoma (>1cm)
• Can also be classed on whether it is sellar or suprasellar (rises out of the sella turcica)
• The majority are benign but can display malignant behaviour (can compress optic chasm due to small space)

Question 3

History and examination of non-functional pituitary tumours

Answer 3

• Long-standing and slow progressing symptoms: Symptoms develop very slowly dye to no hormonal hypersecretion
• Headaches: a pressure symptom
• Bitemporal hemianopia: Due to compression and stretching of the optic chiasm
• Decreased visual acuity: due to palsy of CN III, IV and/or VI

• Erectile dysfunction: due to hypogonadism
• Decreased libido: hypogonadism
• Amenorrhoea: hypogonadism
• Infertility: hypogonadism
• Gynaecomastia, soft testicles: hypogonadism

• Weight gain: hypothyroidism
• Dry skin, hair loss, low mood: hypothyroidism

• Fatigue: hypoadrenalism, hypothyroidism and hypogonadism
• Anorexia: adrenal insufficiency
• Nausea/vomiting: adrenal insufficiency
• Weakness: adrenal insufficiency

Question 4

Investigations for non-functional pituitary tumours

Answer 4

• Prolactin
• Insulin-like growth factor 1
• LH and FSH
• Early morning testosterone
• TSH and T4
• Early morning cortisol
• Insulin induced hypoglycaemia stress test: would see blunted cortisol and growth hormone release
• PITUITARY MRI: FOR RADIOLOGICAL DIAGNOSIS OF pituitary tumour

Question 5

Treatment of non-functional pituitary tumours

Answer 5

Micro-adenoma, asymptomatic:
1) Observation: some may shrink and remain unchanged

Symptomatic:
1) Hormone replacement where needed:
◦ If experiencing symptoms, replace the necessary hormones:
◦ Prolactin CANNOT be replaced

						◦ GH deficiency: assess Quality of life score, then give daily injection . Monitor using QoL score and IGF-1 levels

						◦ ACTH deficiency: replace the glucocorticoids (using prednisolone or hydrocortisone) and the mineralcorticoids (using Fludrocortisone). 
						◦ Must be told the sick day rules: wear steroid bracelet, double glucocorticoid dose if ill and use IM steroids if unable to take tablets
						◦ Give steroids BEFORE levothyroxine due to adrenal crisis risk (hypotension, dizziness, collapse)

						◦ TSH deficiency: Replace thyroxine with Levothyroxine once daily 

						◦ FSH/LH deficiency: 
						◦ In MEN: If fertility required= take gonadotropin injections to induce spermatogenesis (monitor via semen sample)
						◦ In MEN: if fertility not required= replace testosterone (topical or IM)
						◦ In WOMEN: if fertility required= IVF
						◦ In WOMEN: if fertility not required= replace oestrogen (oral or topical), take progesterone if intact uterus to reduce risk of endometrial cancer

Causing visual field defects:
1)Trans-sphenoidal surgery: remove the tumour to reduce compression on optic chiasm
Consider radiotherapy for any residual tumour

Question 6

Complications and prognosis of non-functional pituitary tumours

Answer 6

• Pituitary apoplexy: rapid pituitary enlargement due to haemorrhage into the tumour. Can cause cardiovascular collapse. Seen with acute onset headache, meningism, reduced GCS etc

Generally have good prognosis
Small risk of tumour growth
Treat early with hormone replacement