Introduction: Mesenchymal chondrosarcoma is a subtype of chondrosarcoma, a tumor of cartilaginous origin. Although 20 to 25% of these tumors are extra-skeletal, when they involve the central nervous system the location is usually intracranial. Thereby primary spinal intradural mesenchymal chondrosarcomas are rare.

Case report: The authors report the case of 16 year old female patient, who presented with right lower limb pain and progressive paraparesis. Neurological examination revealed an assymetrical paraparesis, with grade 3 strength on the left lower limb and grade 4 strength on the right lower limb, without sensory deficits or sphincter involvement. The magnetic resonance imaging (MRI) of the spine showed an intra-dural, extra-medullary L1 lesion with homogeneous contrast enhancement. The brain MRI excluded other lesions in the central nervous system. She underwent a T12-L1-L2 laminoplasty and total removal of the tumor under evoked potentials and electromyography monitoring. The pathological examination was compatible with mesenchymal chondrosarcoma. After surgery there was a complete recovery of the neurological deficits. The patient was referred to the oncology clinic for adjuvant therapy.

Discussion: With the report of this case the authors intend to emphasize that although primary extra-skeletal spinal mesenchymal chondrosarcoma is a rare entity, this tumor should be included in the differential diagnosis of intradural extramedullary lesions, especially in pediatric patients.