Abstract
Multiple myeloma (MM) is a malignant plasma cell neoplasm characterized by the accumulation of plasma cells in the bone marrow, the subsequent destruction of bone and organ dysfunction. The present study describes the case of a 66-year-old male patient who presented with the typical clinical manifestations of MM. The patient was administered a bortezomib and dexamethasone regimen for 2 cycles and achieved complete remission. Lenalidomide, vincristine, pirarubicin, dexamethasone, melphalan and thalidomide was used successively in consolidation therapy and maintenance therapy. The patient developed secondary B-cell lymphoblastic leukemia 38 months after the primary MM diagnosis was made. Owing to the exposure of the patient to a variety of therapeutic agents, it could be inferred that multiple immune defects may have played an important role in the secondary lymphoblastic leukemia of the patient. Microscopic examination and flow cytometry detection were important in identifying the secondary malignancy in this MM case.