A case of type III cystic sacrococcygeal teratoma.

We report a rare case of congenital type III cystic teratoma that may be falsely diagnosed as an anterior sacral meningocele. A female newborn baby presented with a long, white-colored 4 x 1 cm coccygeal cyst posterior to the anus. Magnetic resonance imaging (MRI) demonstrated that a 10 x 4 cm elliptical intrapelvic and -abdominal mass anterior to the sacrum and coccyx extended inferiorly to the retrorectal space. We intraoperatively found that the cyst consisted of a mostly thin, white wall, but also with small posterior narrow nodules. We suggest that all cysts in the sacrococcygeal area should be excluded from teratoma carefully, with MRI.