EP07.78: Giant type III sacrococcygeal teratoma: prenatal evolution and postnatal outcome

A 17-year-old woman, G1P0, referred to our specialised tertiary clinic at 21 weeks from regional perinatal centre, diagnosis: “Abdominal mass of unclear origin, left-sided grade 1 hydronephrosis. CHD: ventricular septal defect”. US scan revealed a heterogeneous hypoechoic structure 49x25x36mm located in fetal pelvis and abdominal cavity, which continued externally into sacrococcygeal region (external size 33x31mm). Doppler US: low velocity (15 cm/s) arterial flow vessel from the internal sacrococcygeal region, and a few other vessels. Mass caused displacement of urinary bladder anteriorly, mild ureter dilation, bilateral pyelectasis. Consilium with pediatric surgeon, final diagnosis: “sacrococcygeal teratoma (SCT) type III. VSD”. Woman opted to continue the pregnancy. Follow-up scans at 28 and 35 weeks: internal part heterogeneous hypoechoic, 73x45mm and 84x70mm correspondingly, external part heterogeneous hypoechoic with cysts 60x56x46mm and 90x82x79 mm, feeding vessel velocity 39 cm/s and 45 cm/s; mild cardiomegaly progressed into moderate, bilateral pyelectasis - into right–sided grade III hydronephrosis. Additional finding at 35 weeks bilateral mild/moderate pulmonary hypoplasia. On both follow-up scans no fetal hydrops, anemia or other Doppler changes. Delivery by Caesarean section at 36 weeks, neonate girl 3030 gram, Apgar 7-7, external tumour size 120x90x70 mm. Extensive preoperative examinations, angiography with selective endovascular occlusion of the SCT feeding arteries on 6th day of life. Technically challenging operation on 7th day of life: combined subtotal excision of SCT (8 hours). Pathology: mature teratoma (degree 0). Postoperative period: on day 15th thrombosis of the distal part of the abdominal aorta, distally to a. inferior mesenteric, anticoagulant therapy. Serum AFP pre-op >30000 IU/ml (N<15700), 1 month after OP 729 IU/ml. The infant discharged home on day 43 post-op. Control duplex scan at 6 months - complete recanalisation of the arteries after thrombosis of the abdominal aorta.