Castleman's disease in the retropharyngeal space: CT and MR imaging findings.

We report CT and MR imaging findings in a case of Castleman's disease involving the retropharyngeal space in a middle-aged woman. On CT scans, a well-marginated, homogeneous, and densely enhancing mass was detected in the right retropharyngeal space. The mass was isointense to the muscle on T1-weighted MR images, hyperintense to the muscle on T2-weighted MR images, and showed homogeneous, strong enhancement on contrast-enhanced T1-weighted MR images. The linear hypointense signal in an arborizing pattern was observed within the mass on all pulse sequences.