What are the main findings?
Enlarged and vividly enhancing pituitary with extension up the infundibulum.
What is the differential?
Statistically this most likely represents a pituitary macroadenoma, although possible thickening of the infundibulum does make it less likely. An infiltrative condition such as lymphocytic hypophysitis / neurosarcoidosis is considered less likely especially given the presentation. Lymphoma of the pituitary, although rare, still needs to be considered.
Pre-and post contrast scans were performed through the pituitary fossa including dynamic images (not shown). The pituitary is enlarged, measuring 10 x 10 x 11 millimetres in orthogonal planes. There is triangular tapering toward the infundibulum. The infundibulum demonstrates equivocal thickening with a possible focus of restricted diffusion within the superior part of the gland. A small 4 mm area of hypo enhancement is seen in the left inferior pituitary. The cavernous sinuses have a normal appearance.