Non-Secretory Multiple Myeloma Associated With High-Risk Phenotype and Complex Cytogenetics Including t(8;22).

Abstract

Multiple myeloma (MM) is a plasma cell dyscrasia which is typically characterized by identifiable paraprotein in the blood or urine. However, the minority of patients in whom paraprotein cannot be identified are designated non-secretory MM (NSM). Evaluation of treatment response is more difficult in these patients as paraprotein levels cannot be followed. A dearth of clinical trials including these patients exists because of an inability to measure response by classical serum and urine measurement mechanisms as well as seemingly decreased overall survival compared to secretory MM. NSM is subdivided into four subgroups: "non-producers", "true non-secretors", "oligosecretors" and "false non-secretors". The "non-producers" phenotype is associated with more aggressive disease course. Translocations such as those involving the proto-oncogene c-MYC (chromosome 8) and the lambda light chain gene IGL (chromosome 22) - more commonly associated with Burkitt lymphoma - are rare in MM. We describe a 60-year-old male with NSM who was identified as having multiple high-risk features including complex cytogenetics and a non-producer phenotype, which are features not considered in conventional MM staging and risk stratification. This case highlights the need for awareness of phenotypes and cytogenetics associated with higher clinical risk that are not included in the revised International Staging System.