I would like to submit a letter to the editor regarding the article “Multiple myeloma invasion of the central nervous system,” which recently appeared in the ARCHIVES.
Schluterman et al1 retrospectively described 23 patients with multiple myeloma (MM) and neoplastic meningitis (NM) from the University of Arkansas for Medical Sciences, a nationally recognized center of excellence for the care and treatment of patients with MM. The rarity of this central nervous system complication and the volume of patients seen with MM are easily appreciated by the observation that of approximately 2000 patients seen with MM over a 13-year epoch, 23 were diagnosed with MM-related NM. Proof of NM required positive cerebrospinal fluid (CSF) cytology, a requirement that likely underestimated the true frequency of occurrence because 50% or more of patients have negative CSF cytology based on a large autopsy series.2 In addition, 70% of patients were reported to have findings consistent with NM by magnetic resonance neuroradiography. This figure is higher than those in several other reports describing NM radiography and suggests either delay in diagnosis of NM (and therefore patients with advanced NM) or poor prognostic patients with MM-related NM.3,4 Neoplastic meningitis and bulky central nervous system disease defined radiographically have previously been shown to predict for poor survival, an outcome notable in this series (median survival 3 months after NM diagnosis).5
Chamberlain MC. Commentary Regarding Neoplastic Meningitis Secondary to Multiple Myeloma. Arch Neurol. 2005;62(5):833. doi:10.1001/archneur.62.5.833