CASE REPORT Terminal Myelocystocele and Sacrococcygeal Teratoma: A Comparison of Fetal Ultrasound

SUMMARY: This case exemplifies the difficulty in differentiating cystic sacrococcygeal teratoma and terminal myelocystocele. Fetal sonography presentation and perinatal risks of sacrococcygeal tera-toma and terminal myelocystocele are compared, and we emphasize the importance of obtaining fetal MR imaging to establish an accurate diagnosis. The terminal spine presents unique imaging challenges, par-ticularly in the case of large cystic masses. In the first case, an isolated terminal myelocystocele mimicked a cystic sacro-coccygeal teratoma (SCT) on prenatal sonography. The sec-ond case of type 2 (SCT) is presented for comparison. We discuss the presentation and perinatal risks of these 2 cystic sacrococcygeal masses and illustrate surgical correction of a cystic terminal myelocystocele