Prenatal diagnosis of giant sacrococcygeal teratoma

Objective 

Sacrococcygeal teratomas constitute more than half of all fetal tumors, their incidence is only 1:40,000 live births, with a female-to-male ratio of 4:1. They originate during embryonic development when the primitive streak fails to differentiate among mesodermal, ectodermal and endodermal tissues in the embryonic disc. Characteristics of the neoplasm include internal calcifications, haemorrhage, necrosis of the tumour and degeneration of the cystic neoplasm.The effects of the mass may lead to dystocia and preterm labour. The highly vascular tumour may result in high-output cardiacfailure and eventually foetal hydrops. Advances in ultrasonography have enabled accurate early diagnosis of sacrococcygealteratomas when they present in the form of cystic, solid, or mixed masses that form starting in the sacral region and protrude toward the perineum or buttocks. However, cystic sacrococcygeal teratomas may be erroneously diagnosed as anterior sacral meningomyelocele, especially when they present as posterior cystic masses.

Methods 

We present a case of solid-cystic sacrococcygeal teratoma that was diagnosed in the 18 week of pregnancy by means of two-dimensional ultrasonography in association with color Doppler.

Case(s)

A 34-year-old patient, gravida 2 para 1, with 18 weeks of gestation has presented for routine fetal examination. The ultrasonographic examination revealed a bulky mass (89x59 x 67 mm) at the sacral area that was predominantly solid and had a few cystic components with internal flow seen on color Doppler. No other fetal abnormalities were detected. The patient and her husband were counseled about the prognosis. The patient was referred for fetal surgery. Before this process, a new ultrasound examination revealed fetal demise. The parents opted for termination of pregnancy. The postnatal macroscopic findings confirmed the prenatal diagnosis.

Conclusion 

Advances in ultrasonography have enabled accurate early diagnosis of sacrococcygeal teratomas. Ultrasound scans are also necessary to monitor the tumor size, extension into adjacent structures, tumor vascularity, evidence of cardiac failure, determining time and mode of delivery.

Keywords

Fetal anomaly, prenatal diagnosis, sacrococcygeal teratoma.