Review of Pediatric Extraosseous Chordomas with a Unique, Illustrative Case

Abstract

Introduction: Chordoma is a rare, aggressive tumor that is believed to originate from notochord remnants. It can occur anywhere from the clivus to the sacrum and often recurs even after resection and radiotherapy. We present a unique case that initially suggested a different pathology based on imaging and presentation but was found to be a chordoma on gross and pathological analysis.

Case presentation: An 11-year-old girl presented outpatient for scoliosis evaluation and was found to have what appeared to be a right L4 peripheral nerve sheath tumor on MRI, causing dextroconvex scoliosis. She underwent a gross total resection via a retroperitoneal approach and was found to have what appeared to be an extraosseous, extradural, extra-spinal canal lumbar chordoma. Immunohistochemical features on surgical pathology were consistent with chordoma. The patient was referred to radiation oncology for adjuvant radiotherapy and pediatric hematology/oncology for recurrence monitoring.

Discussion: Our case is the first to present in such a manner, was shown to be external to the spinal canal, encasing the nerve root, and was the first such case in a pediatric patient. We reviewed the growing body of literature on spinal extraosseous chordomas and their characteristics within the pediatric patient population. We also reviewed chordoma pathogenesis theories as well as current and future treatment options.

Keywords: Extraosseous chordoma; Lumbar chordoma; Pediatric chordoma; Spinal oncology.

Fig. 1

a Coronal T2: A T2 hyperintense mass widening the right L4-L5 neural foramen and scalloping the posterior aspect of the L4 vertebral body, extending into the right paraspinal soft tissues including the psoas musculature. b Sagittal STIR: there is edema in the posterior aspect of L4 vertebral body as well as the right posterior elements. c Axial T2: hyperintense mass widening the right L4-L5 neural foramen and scalloping the posterior aspect of the L4 vertebral body, extending into the right paraspinal soft tissues including the psoas musculature. d Post-contrast axial T1 shows marked enhancement in the lesion.

Fig. 2

a Coronal T2: decompression of the right L4-L5 neural foramen, scalloping of the posterior aspect of the L4 vertebral body still present, no apparent residual tumor in the right paraspinal soft tissues and the psoas musculature is intact. b Sagittal STIR: slight reduction in edema in the posterior aspect of L4 vertebral body as well as the right posterior elements. c Axial T2: complete resection of the mass but widening the right L4-L5 neural foramen and scalloping the posterior aspect of the L4 vertebral body is still present, no residual mass seen in the right paraspinal soft tissues including the psoas musculature. d Post-contrast axial T1 shows no enhancement in the area where the lesion was indicating gross total resection.

Fig. 3

a Section of the tumor shows lobular pattern of short cords of eosinophilic epithelioid cells impeded in a myxoid stroma (H and E, ×40 magnification). b Section of the tumor highlights the physaliphorous cells along with the epithelioid tumor cells (H and E, ×400 magnification). c The neoplastic cells show immunoreactivity for pan-cytokeratin (×400 magnification). d The neoplastic cells show diffuse and strong nuclear staining for brachyury (×400 magnification).