Plasma cell leukemia: a rare condition.

Plasma cell leukemia (PCL) is a rare lymphoproliferative disorder characterized by a malignant proliferation of plasma cells in the bone marrow and peripheral blood. PCL is also characterized by a fulminant course and poor prognosis. Diagnosis of PCL is established based on Kyle's criteria which include an absolute plasma cell number comprising greater than 20% of peripheral blood cells. PCL has two variants: the primary form presents de novo in patients with no previous history of multiple myeloma (MM) and the secondary form consists of a leukemic transformation in a previously recognized MM. In this paper, we report ten cases of PCL occurring since 1994 to 2005 in a Mexican health institution. Median age at presentation in our study was 58 years, most of them were female (70%). Primary PCL (PPCL) represented 80% and secondary PCL (SPCL) 20%. We describe clinical characteristics, stage, and response to treatment. Interestingly, we report a patient who presented a secondary PCL and acquired activated protein C resistance (APC-R). Additionally, we found an incidence of 20% of venous thrombosis events in two patients with PPCL. Mean survival was 5.9 months (range 2-17) for both PPCL and SPCL. Mean survival for PPCL was 6.75 months and for SPCL 2.0 months, similar to previous literature reports.