Extramedullary hematopoietic tumor mimicking a thoracic nerve root schwannoma.

Extramedullary hematopoiesis secondary to chronic anemia is well reported throughout the literature. A rare presentation of this condition is in the central nervous tissue reported most frequently as an epidural mass causing spinal cord compression. The authors report the case of a 51-year-old man with beta-thalassemia and chronic anemia who was found to have a 4-cm paravertebral mass suggestive of a schwannoma. The patient underwent transthoracic resection of the mass. Histological examination confirmed an extramedullary hematopoietic tumor. In this article the authors propose a method to distinguish extramedullary hematopoietic tumors from schwannomas. To the authors' knowledge, this is the first reported case in the neurosurgical literature of this phenomenon.