Necrotizing infundibulo-hypophysitis: an entity too rare to be true?

We report a young woman with sudden and severe retroorbital headache, neck pain, and a large sellar mass extending to the suprasellar cistern. A presumptive diagnosis of non-secreting pituitary macroadenoma undergoing apoplexy was made and transphenoidal surgery performed. Histopathology revealed mononuclear infiltration and marked non-hemorrhagic necrosis of the anterior pituitary consistent with a diagnosis of necrotizing infundibulo-hypophysitis. The possible pathogenesis of this rare variant of hypophysitis is discussed.