A 36-year-old woman(G1P0) with no remarkable history was referred to our clinic  at the 25 weeks of pregnancy. Abdominal circumference was larger than expected gestational age. Polyhydramnios was noted. Our ultrasound examination between 25-29 weeks revealed the following findings:

Bilateral pelvicalyceal dilatation, a giant  mass in the abdomen. Note the dilated umbilical arteries. Both intraabdominal umbilical arteries course more lateral than usual  due to compression of  the mass in the abdomen.

Predominantly solid and highly vascularized intraabdominal mass. Dilated bladder and ascites.

Baby after delivery with abnormally distended abdomen. The abdominal mass during operation.

After PPROM, the fetus (3135 gr) was delivered via cesarean section at 32 weeks. Radiologic examination confirmed the intraabdominal mass. The neonate was operated 6 days after delivery. A 13-10 cm retroperitoneal mass originating from coccyx was excised with coccyx. The pathologic diagnosis was immature teratoma grade 3. Final diagnosis was  Sacrococcygeal Teratoma type 4. The baby passed away after operation.

References

Sacrococcgyeal Teratoma https://sonoworld.com/TheFetus/page.aspx?id=530

COW 276 https://sonoworld.com/TheFetus/case.aspx?id=2803

Ayed A, Tonks AM, Lander A, et. al. A review of pregnancies complicated by congenital sacrococcygeal teratoma in the West Midlands region over an 18-year period: population-based, cohort study. Prenat Diagn 2015; 35: 1037-1047.