A sagittal T2-weighted magnetic resonance image at the midline. An intracranial mass is seen protruding dorsally from the pituitary fossa (white arrows). The fossa is widened owing to invasion of the sphenoid bone locally. A ‘mass effect’ is resulting in mild caudal cerebellar herniation through the foramen magnum (black arrows) and compression of the interthalamic adhesion (circled). Mild caudal transtentorial herniation is also seen