A pituitary abscess showing high signal intensity on diffusion-weighted imaging.

The utility of diffusion-weighted imaging (DWI) for the diagnosis of intracranial abscesses has already been established. However, the use of DWI for pituitary abscesses has not been previously reported. We present a case of postoperative pituitary abscess in which T1-weighted and T2-weighted magnetic resonance imaging (MRI) revealed a supra-sellar cystic mass, with the cyst contents showing high intensity on DWI. This case suggests that DWI is useful for the diagnosis of pituitary abscesses.