Fetal Oropharyngeal Teratoma: Ultrasonographic Diagnosis and Unfavorable Perinatal Outcome. A Case Report

Introduction: Fetal oropharyngeal teratoma, or epignathus, is an extremely rare congenital malformation that represents less than 2% of congenital teratomas. Its main clinical relevance lies in the risk of complete obstruction of the fetal airway and perinatal death. Reported cases are typically diagnosed in the third trimester or at birth; however, ultrasound detection in the second trimester remains exceptional. This case provides evidence of early prenatal diagnosis of an epignathus with intrauterine demise in a resource-limited setting. Case presentation: A 20-year-old primigravida with prenatal care beginning at nine weeks presented at 27.2 weeks with rapid abdominal enlargement and a sensation of abdominal tension. Structural ultrasound revealed a heterogeneous oropharyngeal mass measuring 7.5 × 5.7 cm, associated with severe polyhydramnios, pleural effusion, ascites, and nonimmune fetal hydrops. No fetal heart rate was detected. Differential diagnoses included lymphangioma, branchial cleft cyst, rhabdomyosarcoma, and anterior encephalocele, with a presumptive diagnosis of oropharyngeal teratoma (epignathus). Labor induction was performed using 25 µg of vaginal misoprostol every 4 hours, resulting in the delivery of a female fetus weighing 700 g with a 6 × 6 cm oropharyngeal mass causing complete airway obstruction. The mother had a favorable postoperative course without complications. Conclusion: Early prenatal diagnosis of oropharyngeal teratoma is essential for planning care in specialized centers capable of advanced perinatal management. This case is unique due to its second-trimester diagnosis and comprehensive ultrasonographic correlation, contributing valuable information to the existing medical literature. The key takeaway is that timely sonographic suspicion, even in resource-limited settings, allows for diagnostic orientation, genetic counseling, and the provision of comprehensive and compassionate care in the setting of adverse fetal outcomes.