In Utero Autoamputation of a Fetal Sacrococcygeal Teratoma: A case report

Abstract

Introduction: Sacrococcygeal teratomas are typically benign tumors containing endoderm, mesoderm, and ectoderm derived tissues. They are the most common extragonadal fetal tumor and arise from the sacrococcygeal junction. These tumors can have varying levels of intrapelvic involvement, which serves as the basis for their classification system. Case presentation: This case report describes the interesting prenatal and postnatal course of a newborn with a sacrococcygeal teratoma, identified at 24 weeks via ultrasound, which underwent in utero autoamputation. Ultrasound at 34 weeks gestation revealed the teratoma freely floating in the uterine cavity. The patient was delivered via cesarean section at full term, along with the teratoma. Postnatal spinal ultrasound and MRI revealed a remaining intrapelvic portion of the mass which required surgical resection. Approximately 15 months post resection, the patient's surveillance AFP level was elevated. Cross sectional imaging revealed a 5cm solid mass in the presacral space. The patient ultimately received chemotherapy and additional resection for recurrence. Conclusion: Sacrococcygeal teratomas are a common fetal tumor with varying presentations documented in the literature. The most common presentation is a sacral mass, with variations dependent on size, location, and extension of the tumor. Our patient's presentation of a type I tumor undergoing in utero autoamputation is believed to be the first of its kind. Alternatively, our case could possibly be a yet undescribed mechanism for type IV tumors, which have no external component.

Keywords

• Sacrococcygeal teratoma
• In utero autoamputation
• Case report