Magnetic resonance imaging and computerized tomography images in a case of pituitary abscess

A 29-year-old male patient with clinical manifestations of panhypopituitarism and diabetes insipidus is presented. The clinical and laboratory evaluation of the pituitary reserve confirmed a total pituitary insufficiency. Computed tomography (CT) scan demonstrated a low-density lesion suggesting a pituitary tumor with suprasellar extension, and magnetic resonance imaging (MRI) revealed a pituitary mass with decreased signal intensity on T1-weighted images and capsular contrast enhancement after gadolinium injection. The surgical procedure was the treatment of choice. During surgery a large amount of purulent material was removed. With light microscopy, chronic nonspecific inflammation and a pituitary abscess capsule were demonstrated in the tissue. The results of the cultures revealed coagulase negative staphylococcus. The post-operative course was uneventful and, as the patient was pituitary-deficient, he was on replacement therapy and was being followed-up. Pituitary abscess is an exceptional lesion in the literature and despite the advent of CT and MRI, its preoperative diagnosis still remains difficult. However, the presence of an intrasellar expansive process with liquid center and contrast enhanced outline should suggest the possibility of an abscess. Sellar round cystic mass isointense or hypointense to grey matter on T-1, high intensity signal on T-2, or opposite pattern with a peripheral rim enhancement following gadolinium injection, and diabetes insipidus may all be suggestive of a pituitary abscess. (C) 2001, Editrice Kurtis.