Sudden enlargement of a pituitary tumour (usually non-functioning macroadenoma) secondary to haemorrhage or infarction.

Precipitating factors

• hypertension
• pregnancy
• trauma
• anticoagulation

PC

• sudden onset headache similar to that seen in subarachnoid haemorrhage
• vomiting
• neck stiffness
• visual field defects: classically bitemporal superior quadrantic defect
• extraocular nerve palsies

Investigation

• features of pituitary insufficiency
  • e.g. hypotension/hyponatraemia secondary to hypoadrenalism
• MRI is diagnostic

Management