Presacral epidermoid cyst: imaging findings with histopathologic correlation.

BACKGROUND

The aim of this study was to determine the imaging characteristics of presacral epidermoid cysts and correlate the imaging findings with the histopathologic findings.

METHODS

We retrospectively reviewed sonographic, computed tomographic, and magnetic resonance examinations in four consecutive patients with a pathologically proven presacral epidermoid cyst. Imaging findings of the presacral epidermoid cyst were correlated with the histopathologic findings.

RESULTS

In all four patients, sonography showed a presacral mass with a heterogeneous low echogenicity, and computed tomography showed a discrete well-defined hypodense presacral mass with a thin wall. In the three patients who underwent magnetic resonance imaging, the mass showed a heterogeneous low signal intensity on the T1-weighted image and a high signal intensity with multiple small foci of low signal intensity in the nondependent portion of the mass on the T2-weighted image. These imaging findings correlated well with the pathologic results. Aggregates of keratinous material contributed to these imaging findings.

CONCLUSION

In the diagnosis of the presacral epidermoid cyst, sonographic and magnetic resonance imaging findings may be helpful.