Squamous cell carcinoma arising from a presacral epidermoid cyst: CT and MR findings.

We report CT and MRI findings in a case of squamous cell carcinoma arising from a presacral epidermoid cyst, which has not been previously reported. CT findings revealed a focal wall thickening of the anterior wall of the huge presacral cystic mass. The squamous cell carcinoma was more hypointense than the cystic fluid on T1- and T2-weighted images and showed heterogeneous enhancement on contrast enhanced T1-weighted image.