Role of ultrasound in the prenatal diagnosis of sacrococcygeal teratoma: A case study.

Sacrococcygeal teratoma (SCT) is the most common congenital tumor arising from pluripotent cells at the fetal caudal end. Early prenatal diagnosis is essential for appropriate monitoring and management due to potential complications such as polyhydramnios, hydrops fetalis, and high-output cardiac failure. We report a case of a 30-year-old woman whose fetus was diagnosed at 17 weeks' gestation with a 20 mm sacrococcygeal mass detected by two-dimensional ultrasound. Detailed assessment with color Doppler and three-dimensional imaging characterized the lesion as a mixed solid-cystic, highly vascularized tumor consistent with a Type I SCT. Given the associated polyhydramnios and uncertain prognosis, a multidisciplinary team opted for medical termination of pregnancy at 18 weeks, following evaluation the week after diagnosis. Post-delivery examination confirmed the prenatal findings. Prenatal ultrasound remains the primary diagnostic and monitoring tool for SCT, with three-dimensional imaging and Doppler studies enhancing anatomical and vascular evaluation. Magnetic resonance imaging may complement ultrasound by better defining tumor extent and relationships with adjacent structures; however, in this case, fetal MRI was not performed because ultrasound provided sufficient information to guide management, and limited availability made MRI unnecessary. Prognostic factors influencing management include tumor size, vascularization, and associated fetal complications. Early detection facilitates multidisciplinary planning and improves perinatal outcomes. This case highlights the pivotal role of comprehensive prenatal ultrasound in diagnosing and managing sacrococcygeal teratomas and emphasizes that integration of advanced imaging modalities and multidisciplinary collaboration is essential to optimize clinical decisions and counseling in affected pregnancies.