Pituitary abscess: CT and MRI findings.

We report a patient with a pituitary abscess which was incidentally found after he had sustained a head injury. This 61-year-old man had no clinical or laboratory evidence suggestive of a pituitary lesion. A precontrast-enhanced brain computed tomograph (CT) showed a slightly hyperdense tumor. Magnetic resonance imaging (MRI) showed hyperintensity on T1-weighted images, but central hypointensity with peripheral ring-form hyperintensity on proton density-weighted and T2-weighted images. These CT and MRI characteristics may have been attributable to the abundant proteinaceous content of the abscess. Therefore, the appearance of a pituitary abscess in image studies may be variable depending on the abscess composition.