Multiple myeloma with central nervous system relapse

Abstract

Central nervous system involvement in multiple myeloma is a rare complication but carries a very poor prognosis. We provide a review of current literature, including presentation, treatment and survival data, and describe our experience in a regional hematologic malignancy diagnosis center where, over a 15-year period, ten cases were identified. Although the median age of onset, frequently between 50-60 years, is comparatively young, those diagnosed usually have a preceding diagnosis of multiple myeloma and often have had several lines of treatment. We discuss putative underlying factors such as prior treatment and associations including possible risk factors and features suggestive of a distinct biology. Central nervous system involvement may be challenging to diagnose in myeloma, displaying heterogeneous symptoms that can be confounded by neurological symptoms caused by the typical features of myeloma or treatment side-effects. We discuss the clinical features, imaging and laboratory methods used in diagnosis, and highlight the importance of considering this rare complication when neurological symptoms occur at presentation or, more commonly, during the disease pathway. In the absence of clinical trial data to inform an evidence-based approach to treatment, we discuss current and novel treatment options. Finally, we propose the establishment of an International Registry of such cases as the best way to collect and subsequently disseminate presentation, diagnostic and treatment outcome data on this rare complication of multiple myeloma.

Figure 1

Diagnosis and treatment of multiple myelo-ma with central nervous system (CNS) involvement. FDG-PET: fluorodeoxyglucose positron-emission tomography; WCC: white cell count; CSF: cerebrospinal fluid; FLC: free light chain; TP: total protein; ALB: albumin; Ig: immunoglobulins; M-band: monoclonal immunoprotein; CS: corticosteroids; NGNA: next generation novel agents; XRT: radiotherapy; IT: intrathecal therapy; mAbs: monoclonal antibodies.

Figure 2

Detection and characterization of myeloma cells in cerebrospinal fluid by flow cytometry. Clonal plasma cells (blue) distinguished from other lymphocyte populations (red) and debris (black).