Presacral myxopapillary ependymoma presenting as an abdominal mass in a child.

Ependymomas of the sacrococcygeal region almost always arise on the posterior aspect of the sacrum in the soft tissues and subcutaneous tissues of this region. The predominant histologic type of ependymoma in the sacrococcygeal area is myxopapillary. We report a case of myxopapillary ependymoma arising in the presacral area and presenting clinically as an abdominal mass. Ependymomas arising on the ventral aspect of the sacrum are exceedingly rare, and only 24 previous cases have been reported in the English literature. While dorsal myxopapillary ependymomas occasionally metastasize, there have been no reports of metastasis in the presacral tumors of this type.