Intraspinal cervicothoracic junction chondrosarcoma: illustrative case

Abstract

Background: Chondrosarcoma is an uncommon spinal tumor that can present as an extraskeletal mass. Rarely, these tumors present as dumbbell tumors through the neural foramina, mimicking schwannomas or neurofibromas.

Observations: A 46-year-old female presented with 2 years of worsening right-arm radiculopathy. Magnetic resonance imaging of the thoracic spine revealed a peripherally enhancing extramedullary mass through the right T1 foramen and compressing the spinal cord. Computed tomography showed the mass to be partially calcified. She underwent C7-T2 laminectomy and C6-T3 posterior instrumented fusion with gross-total resection of an extradural mass. Pathology revealed a grade I chondrosarcoma. Her symptoms improved postoperatively, with some residual right-arm radicular pain.

Lessons: Intraspinal extradural dumbbell conventional chondrosarcoma is rare, with only 9 cases, including ours, reported. Patient ages range from 16 to 72 years old, and male sex is more common in these cases. The most common location is the thoracic spine, and our case is the only reported one in the cervicothoracic junction. These tumors often mimic schwannomas on imaging, but chondrosarcoma should remain in the differential diagnosis, because management of these tumors differs. Chondrosarcoma may benefit from more aggressive resection, including en bloc resection, and may require adjuvant radiotherapy.

Keywords: MRI = magnetic resonance imaging; case report; cervicothoracic junction; chondrosarcoma; extradural; intraspinal; schwannoma; spinal tumor.

FIG. 1

Axial T1-weighted postcontrast (A) and T2-weighted (B) MRI of the thoracic spine revealing a peripherally enhancing dumbbell tumor displacing the spinal cord and extending through the right T1 neural foramen anteriorly and laterally, causing scalloping of the surrounding bony structures. Sagittal short tau inversion recovery image (C) shows the ventral extent of the tumor and the right T1 foramen expanded by the tumor.

FIG. 2

Axial computed tomography of the chest without contrast, revealing calcification of the mass centrally (black arrow) exiting the right T1 neural foramen.

FIG. 3

Postoperative axial postcontrast T1-weighted MRI of the thoracic spine showing gross-total resection of the mass, a fully decompressed spinal cord, and the hemilaminectomy and facetectomy required for the tumor resection.

FIG. 4

Histological slides of the grade I chondrosarcoma. At low power (A), there was abnormal cartilaginous tissue with increased cellularity. Higher power (B and C) revealed abnormal nuclei and binucleated cells with increased mitosis. Hematoxylin and eosin, original magnification ×10 (A), ×40 (B and C).