Primary extranodal histiocytic sarcoma of lumbar spine.

A 17-year-old male patient presented with lower back pain and weakness of lower limbs. On radiological investigation, a destructive bony lesion involving the third lumbar vertebra was seen associated with soft tissue extension and an extradural component. The lesion was surgically excised in view of the rapidly progressing symptoms. The histologic diagnosis was histiocytic sarcoma. Further investigations did not reveal any other lesion elsewhere. The case is being presented in view of the uncommon occurrence of a primary extranodal histiocytic sarcoma of the lumbar spine, which simulated a primary bone tumor.