Fetal intrapericardial teratoma: natural history and management including successful in utero surgery.

Background: Intrapericardial teratoma is a rare, lethal tumor often detected in fetal life. Tumor mass and pericardial effusion cause cardiac tamponade that, if relieved, could be life-saving. Optimal timing of intervention and methods for effective fetal treatment are unknown.

Objective: We describe our single-center experience with fetal intrapericardial teratoma including the first report of successful in utero surgical resection with survival to term.

Study Design: We reviewed our database for suspected fetal intrapericardial teratoma. On fetal ultrasound and echocardiography tumor size was estimated by calculation of an ellipse and analyzed in relation to Doppler-derived fetal cardiac output, venous flow patterns, hydrops, and outcome.

Results: Eight fetuses with suspected intrapericardial teratoma were seen from 2009 through 2015. Gestational age at initial presentation ranged from 21-34 (median 26) weeks. Two cases mimicked the appearance of intrapericardial teratoma, but had no serial change in cardiac output over time and were ultimately determined to be other types of tumor. In 6 cases of true intrapericardial teratoma, tumor growth was extremely rapid and associated with progressive decline in cardiac output (to <400 mL/kg/min) manifesting in hydrops and death if left untreated. One case was treated successfully at 31 weeks through ex utero intrapartum delivery with tumor resection while on placental support. Another case underwent open fetal surgery and resection at 24 weeks, with resumption of gestation until delivery at 37 weeks with excellent outcome.

Conclusion: Fetal intrapericardial teratoma can be successfully managed utilizing serial surveillance and by treatment in a timely manner prior to the predictable onset of hydrops, determined through increasing tumor size and a declining cardiac output. Surgical resection in utero is possible, with good results.