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Chondroblastoma of the lumbar spine. Report of two cases and review of the literature.

Chondroblastoma is a benign cartilaginous neoplasm that generally affects the appendicular skeleton. Twenty-six cases of spinal chondroblastoma have been reported in the past 50 years, only six of which were located in the lumbar region. The authors report two cases involving this exceptional location. In both patients, low-back pain, in the absence of radicular pain, was the presenting symptom. In both cases, plain radiography and computerized tomography scanning revealed an osteolytic lesion surrounded by marginal sclerosis. Magnetic resonance imaging allowed the authors to study the tumor's local extension. Examination of a percutaneous fluoroscopy-guided biopsy sample revealed the following typical histological features of chondroblastoma: chondroid tissue, focally alternating with cellular areas, and no nuclear atypia or pleomorphism. To reduce the risk of local recurrence, vertebrectomy and anterior-posterior fusion were performed in both cases. In one case, a structural lumbar scoliosis was corrected during the posterior procedure. There was no postoperative complication. No recurrence was observed during the 3- to 6-year follow-up period. The surgery-related results were deemed successful. Although exceptional, the diagnosis of chondroblastoma is possible in lesions involving the lumbar spine. Other spinal locations are described in the literature, and frequency of recurrence is stressed. A vertebrectomy is advised to reduce the risk of local recurrence.