Female, 39 years old, with headache and dizziness, known pituitary mass. A nonenhancing, T1 hyperintense lesion is evident within the posterior aspect of the pituitary gland measuring up to 11 mm TV, 6 mm AP, and 7 mm SI. The normal pituitary glandular parenchyma appears to drape along the superior and anterior aspects of this lesion. The pituitary stalk sits at midline and is normal in appearance. The sellar contents protrude mildly into the suprasellar cistern, but there is no significant impingement on the optic apparatus. No evidence of cavernous sinus involvement is seen.
A nonenhancing, T1 hyperintense lesion is evident within the posterior aspect of the pituitary gland. The differential diagnosis for this finding would include a Rathke cleft cyst, pars intermedia cyst, or perhaps less likely a cystically degenerated or hemorrhagic adenoma.