Magnetic resonance characterization of a long-standing pituitary abscess.

A 56-year-old male patient with panhypopituitarism is presented. Magnetic resonance (MR) examination of the pituitary region revealed a pituitary mass with markedly increased signal intensity on T1-weighted images and low signal intensity on T2-weighted images. At surgery, a large amount of purulent material was removed. At light microscopy, the tissue was demonstrated to be a pituitary abscess occurring in an otherwise normal pituitary gland. The high signal intensity on T1-weighted images does not correspond to the only MR description of a pituitary abscess given until now, reporting a mass isointense to white matter. These signal characteristics could emanate from the presence of small amounts of blood breakdown products in the proteinaceous content of the abscess. MR appearance of a pituitary abscess is possibly aspecific and could depend on the pathological composition of the lesion.