Concurrent chronic neutrophilic leukemia blast crisis and multiple myeloma: A case report and literature review

The current study presents the case of a 78-year-old male with concurrent chronic neutrophilic leukemia (CNL) and multiple myeloma (MM) who developed acute myeloid leukemia after two years of treatment with hydroxyurea, cyclophosphamide, prednisone and thalidomide. The patient presented with mature neutrophilic leukocytosis, hepatosplenomegaly, a high neutrophil alkaline phosphatase score and an absence of the Philadelphia chromosome or the BCR-ABL fusion gene. A bone marrow aspirate smear and biopsy indicated that the CNL coexisted with a plasma cell neoplasm. In addition, monoclonal λ-paraproteinemia was detected by serum protein immunofixation electrophoresis, and bone lesions were identified in multiple vertebrae. The patient achieved complete remission following one cycle of induction chemotherapy with the decitabine regimen in combination with the low-dose cytarabine, aclarubicin and granulocyte-colony stimulating factor (CAG) priming regimen. The occurrence of CNL and MM concurrently is extremely rare and thus, it has only been reported in a small number of cases. The occurrence of CNL and MM in the same patient as two distinct hematological malignancies indicates the neoplastic transformation of a pluripotent stem cell. Decitabine combined with the CAG priming regimen may present a good therapeutic strategy for elderly patients with secondary acute myeloid leukemia.