Anterior sacral meningocele and the scimitar sign. Report of a case.

Anterior sacral meningocele is an unusual lesion that usually presents as a presacral mass. This is a case presentation of a young woman who presented with amenorrhea. On physical examination, a large presacral mass was found. Ultrasonography revealed a large cystic structure. Radiography of the pelvis demonstrated a sacral deformity or "scimitar sign" that is pathognomonic for anterior sacral meningocele. The diagnosis was confirmed by computed tomography with myelographic enhancement.