ABSTRACT
Plasma cell leukemia [PCL] is a rare hematologic malignancy with very poor outcome. It is defined by the presence of >2 · 109/L plasma cells or >20% plasmacytosis of the differential white cell count in the peripheral blood. Primary PCL is first diagnosed in the leukemic phase, while secondary PCL corresponds to the leukemic transformation of a previously diagnosed multiple myeloma [MM]. The incidence of PCL ranges between 2-4% of patients with MM and 0.9% of patients with acute leukemia. In this case series, we describe the clinicopathologic, immunophenotypic, and cytogenetic findings of four patients diagnosed with PCL within a ten-year period [2002-2012] at King Faisal Specialist Hospital and Research Centre [General Organization], Riyadh, Saudi Arabia