Pericoccygeal hidrocystoma.

Abstract

We report the imaging findings of pericoccygeal hidrocystoma in a 52-year-old woman. Sonography showed a large cystic lesion with internal echoes in the pericoccygeal region; it appeared as a well-defined, low-density mass on CT, and as a high-signal-intensity mass on T1- and T2-weighted MR images. Histopathologic examination revealed an apocrine hidrocystoma.