Elevated cerebrospinal fluid b-2 microglobulin as a tumor marker in a patient with myeloma of the central nervous system.

: Myeloma involvement of the nervous system is rare. Extensive literature review revealed only a few cases reported from different parts of the world. The presence of CNS symptoms and detection of plasma cells in the CSF is the usual basis of diagnosis. In addition, immunoelectrophoresis and immunofixation for detection of monoclonal protein confirm the diagnosis in some cases, while some authors used flow cytometry and cytogenetic studies on CSF. Reports of multiple myeloma also include unfavorable cytogenetic abnormalities of chromosome 13. We report a case with relapsed CNS multiple myeloma with the detection of elevated b-2 microglobulin (b2M) as a tumor marker in the CSF.