First trimester diagnosis of sacrococcygeal teratoma using two- and three-dimensional ultrasound.

Sacrococcygeal teratomas are very rarely diagnosed in the first trimester. Here we report a case of a presacral mass suggestive of a sacrococcygeal teratoma that was detected during the first trimester nuchal translucency thickness measurement at 12+1 week of gestation. Although the diagnosis was possible with conventional two-dimensional sonography, three-dimensional sonography facilitated prenatal counseling by providing more recognizable images to the parents. Postmortem examination of the fetus confirmed the presence of a type 2 benign immature teratoma.