[Three cases of pituitary abscess]

We report three cases of pituitary abscess. Three patients, all females, had suffered headache and complained of general fatigue. In each case magnetic resonance imaging (MRI) revealed a sellar mass with suprasellar extension. T1-weighted images revealed an isointense or slightly hypointense lesion with thin ring-enhancement following gadolinium injection. No inflammatory signs were found in two cases. In one case, a gradual change in clinical symptoms and MRI findings was noted: the hypophyseal hemorrhagic lesion detected on MRI changed into a cystic lesion with thin ring-enhancement. Transsphenoidal surgery was performed in all three cases. In each case, however, no organism was cultured and no tumor component was found. It is difficult to diagnose pituitary abscess prior to surgery if no inflammatory signs are present. Diagnosis of this condition requires careful radiological evaluation. Findings of a suprasellar round cystic mass with thin ring-enhancement on MRI associated with thickened stalk, hyperprolactinemia, and diabetes insipidus may be suggestive of a pituitary abscess.