What does this MRI show?
This is a pituitary macroadenoma. The contrast-enhanced images show how it has grown out of the pituitary fossa and is compressing the optic chiasm.
What visual field defect would you expect to find on examination?
This lesion results in a typical bitemporal hemianopia ("tunnel vision"). Often patients will not realise the peripheries are missing from their vision so it is important to examine properly.
As well as formal ophthalmology review, what other tests are important to perform?
Pituitary function should be tested - prolactin, ACTH, growth hormone, gonadotrophins (LH/FSH) and thyroid function. These can be used as markers for severity and also response to treatment.
This MRI shows a large pituitary macroadenoma.
Not only does it grow superiorly (displacing and compressing the optic chiasm) it also invades the sphenoid sinus anteriorly.