What role does skull x-ray have in diagnosis of intracranial pathology?
In current practice (what we modestly refer to as 'modern' imaging) skull x-rays have very little role. In the setting of pituitary tumours they are still obtained prior to surgery (after diagnosis) by some surgeons to help better visualise the operative path.
Is the sella expanded? Where is the floor of the sella?
Yes it is, the floor is displaced inferiorly into the sphenoid (see the next images).
While you are at it identify some other bony landmarks on the lateral xray (e.g. planum sphenoidale, orbital roof, sphenoid sinus, acoustic meatus, mastoid air cells).
Have a look at the next image.
AP and lateral views of the skull show left-sided sellar excavation.