Seated within the left aspect of the pituitary gland a well-defined rounded hypo-enhancing lesion measuring 14x16 mm. Subsequent focal bulge of the glandular contour and contralateral deviation of the stalk are demonstrated, the optic chiasm is not yet contacted or compressed. Grade I invasion of the left cavernous sinus is demonstrated by tumor extending beyond the medial carotid line, but doesn't extend beyond the median one.