A pituitary abscess simulating an intrasellar tumor.

A 16-year-old girl presented with amenorrhea, polyuria, and thirst for eight months and severe headaches for two weeks. An intrasellar mass protruding above the sella turcica was demonstrated by pneumoencephalography. When the tumor was approached surgically by a transsphenoidal route, it was found that the sella turcica contained encapsulated purulent material under pressure. Ampicillin and methicillin had been given preoperatively, and postoperatively she required hormonal replacement therapy for anterior and posterior pituitary hypofunction.