A Rare Neonatal Intramedullary Immature Teratoma Undiagnosed in utero: A Case Report.

Background And Importance: Immature teratoma is a known pediatric tumor. However, spinal variants are rare and can present both a diagnostic and therapeutic challenge, particularly regarding aggression as it pertains to extent of resection, likelihood of recurrence and concordant prognosis, and the need and efficacy of adjuvant therapies.

Clinical Presentation: The patient is a 27-day-old female who presented with 10 days of poor feeding, irritability, and progressive hypotonia. Although upon immediate presentation emergency providers' differential diagnoses included meningitis, inborn error of metabolism, and genetic neurodegenerative disease, a subsequent magnetic resonance (MR) imaging of the total spine revealed a large intradural intramedullary mass extending from the medulla to the thoracic cord at T12. The patient underwent multilevel cervical and thoracic laminectomies/laminoplasty for maximal safe resection. Histopathology revealed mostly mature tissue elements originating from all 3 germ layers, interspersed with foci of immature neuroepithelium, consistent with grade 1 immature teratoma. Following surgical intervention, the patient regained strength and spontaneous movement and underwent physical therapy. Follow-up MR imaging of the total spine was obtained every 3 months, and at 9 months, recurrence was demonstrated, which was successfully treated with chemotherapy. Further surveillance MR imaging of the total spine has demonstrated cystic myelomalacia changes without definite tumor recurrence, at 5-year follow-up. Clinically, the patient has developed scoliosis without weakness, pain, or urinary symptoms.

Conclusion: This case demonstrates an exceptionally rare and unusual variant neoplasm in a neonate and highlights the difficulty of diagnosis and the important role of MR imaging. It also illustrates the importance of gross total resection, the risk of recurrence, and the need for close radiographic follow-up of these lesions. It also provides a useful example of the efficacy of adjuvant chemotherapy in treating recurrence.