Lumbar spinal canal osteosarcoma: A case report.

RATIONALE: Osteosarcoma is a rare neoplasm in the lumbar spine. Although osteosarcoma can arise in any portion of the skeleton, it very rarely arises in the spinal canal, which accounts for <0.1% of all cases of adult sarcomas. Here, we describe a case of osteosarcoma arising in the L4-5 spinal canal.

PATIENT CONCERNS: The present report describes the case of a 55-year-old female patient with osteosarcoma of the L4-5 spinal canal.

DIAGNOSES: The patient was initially diagnosed with lumbar spinal stenosis and underwent lumbar fusion at a local hospital. At the 4-month follow-up, the patient reported a marked increase in numbness and pain in the lumbar region and lower limbs. Based on magnetic resonance imaging, we diagnosed a postoperative infectious lesion of the lumbar spine.

INTERVENTIONS: The patient underwent surgery for complete removal of the mass lesion. The mass measured 3 × 2.5 × 0.7 cm in size and was located in the L4-5 spinal canal.

OUTCOMES: Based on histological and immunohistochemical findings, the diagnosis of osteosarcoma was confirmed by an expert pathology consultant. The patient then received chemotherapy. Postoperative follow-up at 6 months revealed no evidence of recurrent disease or residual side effects from therapy.

LESSONS: Osteosarcoma in the L4-5 spinal canal is extremely rare and very difficult to distinguish histologically from benign nervous and fibrous tissue. This is a very valuable case, which highlights the need for orthopedic surgeons to consider this when diagnosing patients with spinal tumors.