Central nervous system meningeal myelomatosis: a biochemical approach to a haematological disorder

Abstract

Introduction Neurological complications occur in up to 50% of multiple myeloma (MM) cases, least commonly due to direct CNS involvement by meningeal myelomatosis (CNS MM), isolated cerebral plasmacytoma or localised intraparenchymal lesions. CNS MM occurs in 1% of cases. We report on the biochemical features of one such uncommon presentation. Aim To describe the role of cerebrospinal fluid (CSF) biochemical markers in the diagnosis, treatment monitoring and disease progression in CNS MM. Case history A 56-year-old female presented with a short history of bone pains, anaemia, hypercalcaemia, hyperglobulinaemia and lytic bone lesions. She was diagnosed with IgA (kappa) MM stage 2A. Despite chemotherapy, she developed pleural effusions, ascites and subsequently neurological manifestations over 12 months. Spinal magnetic resonance imaging (MRI) showed extensive myelomatosis with demonstration of CSF monoclonal plasma cells. She received intrathecal chemotherapy and cranial radiotherapy with partial improvement but died 6 weeks after recognition of CNS involvement. CSF analysis demonstrated evidence of intrathecal immunoglobulin synthesis. IgA intrathecal fraction and absolute levels of CSF IgA, free kappa light chains, ferritin and β 2 microglobulin were initially elevated and later dropped with treatment. Importantly, this drop coincided with symptomatic improvement. Conclusion CSF biochemical markers may be useful in diagnosing and monitoring CNS MM.