Plasma cell leukemia (PCL) is rare cancer involving a subtype of white blood cells called plasma cells. Plasma cell leukemia is one of the most aggressive human neoplasms; fortunately it constitutes 2% to 4% of all cases of plasma cell disorders. The WHO criterion for diagnosis of PCL is that plasma cells constitute more than 20% of cells in the peripheral blood with an absolute plasma cell count of more than 2 × 109/L. The presentation may be primary, de novo, or secondary, evolving from an existing case of multiple myeloma as part of the terminal phase of the disease. Approximately 60 to 70% of cases are primary
Diagnosis based on plasma cell proliferation in the blood at presentation
Treatment of plasma cell leukemia is by supportive care and systemic chemotherapy. Combination of cyclophosphamide, doxorubicin, vincristine, and prednisone (or dexamethasone) can be used. A second combination is the use of cyclophosphamide, dexamethasone, and thalidomide as for myeloma. Another regimen termed VMCP/VBAP uses alternating vincristine, melphalan (M), cyclophosphamide, prednisone/vincristine, carmustine, doxorubicin, and prednisone polychemotherapy. In general, comination chemotherapy has resulted in median survivals of 18 to 20 months compared to 2 to 6 months when single agent therapy is used.