Sudden headache, visual loss or ophthalmoplegia with a sellar mass: haemorrhage or infarction inside a (usually undiagnosed) macroadenoma — MRI shows blood products, chiasm compression and cavernous sinus involvement.
Orient first
- Apoplexy is haemorrhage or infarction of a pituitary adenoma; it is an endocrine emergency (acute hypocortisolism).
- On CT the mass may be hyperdense; MRI shows the blood products, or a non-enhancing infarcted gland with an enhancing rim.
- The differential: Rathke cleft cyst with proteinaceous content, aneurysm (must not be biopsied), craniopharyngioma.
Acquire the study
- Coronal and sagittal T1 (≤ 3 mm), coronal T2, SWI or gradient echo, post-contrast T1.
The manoeuvre
- Pre-contrast T1: hyperintense blood within the mass (subacute), fluid–fluid level.
- Post-contrast T1: peripheral rim enhancement around a non-enhancing infarcted centre.
- Coronal T2: optic chiasm displacement and signal; cavernous sinus invasion (Knosp grade).
- SWI: blooming haemosiderin.
- Sphenoid sinus mucosal thickening is a common associated sign.
What confirms it
- A sellar mass with haemorrhage or infarction and a compatible acute clinical picture.
What licenses you to exclude it
- A normal pituitary on dedicated MRI excludes apoplexy.
The classic misread
- Missing an aneurysm arising from the cavernous carotid — look for flow void and pulsation artefact.