A Rare Case of Altman Type I Sacrococcygeal Teratoma: Late Antenatal Diagnosis and Successful Multidisciplinary Management

Abstract

Background: Sacrococcygeal teratoma (SCT) is a rare congenital germ cell tumour that may require coordinated antenatal and neonatal management. Case Presentation: A 27-year-old gravida 2, para 1 woman underwent a third-trimester growth ultrasound at 31 weeks and 1 day, which identified a midline solid-cystic exophytic lesion at the fetal caudal end. Fetal MRI demonstrated a 6.0 × 6.4 × 9.0 cm sacrococcygeal mass without intrapelvic or intraspinal extension, hydrops, cardiomegaly, or pelvic-organ compression, consistent with Altman Type I SCT. Following multidisciplinary planning, the patient presented in spontaneous labour at 38 weeks and 4 days and underwent emergency caesarean section. A live female neonate weighing 3.14 kg was delivered with an 8 × 10 cm sacrococcygeal mass. Postnatal MRI confirmed a predominantly external solid-cystic lesion without intraspinal extension. Complete tumour excision with coccygectomy was performed on postnatal day 6. Histopathological examination showed a mature teratoma composed of well-differentiated tissues from all three germ layers, without immature or malignant elements, and all margins were clear. Postoperative wound dehiscence was managed by secondary suturing and wound care. The neonate was discharged on postoperative day 10 without urological, anorectal, or neurological dysfunction. Conclusion: Third-trimester detection, fetal MRI, planned multidisciplinary care, appropriate delivery, and early complete excision with coccygectomy supported a favourable short-term maternal and neonatal outcome. Continued clinical, imaging, and alpha-fetoprotein surveillance remains necessary.