Nonsecretory primary plasma cell leukemia with good response to thalidomide-based treatment.

Primary plasma cell leukemia (PCL) is a rare hematologic disorder with distinct features. The criterion for the diagnosis of PCL is based on the finding of malignant plasma cells in the peripheral blood (more than 2 x 10(9)/L or more than 20% of white blood cells). We report a case of a 74-year-old patient with primary nonsecretory PCL. Examination of blood smears led to the diagnosis of PCL, which was confirmed by bone marrow biopsy. Due to the patient's impaired general condition, intensive chemotherapy could not be administered. After an oral induction chemotherapy consisting of cyclophosphamide and high dose dexamethasone followed by one cycle of high-dose dexamethasone and thalidomide no evidence of the disease in the peripheral blood was detectable. Consequently, the patient was put on a thalidomide maintenance therapy. Six months after first diagnosis, the patient was found to have bone marrow and peripheral blood relapse with anemia and neutropenia in the clinical context of acute on chronic renal failure. After a limited response to further chemotherapy, the patient died 14 months after the first diagnosis while on dexamethasone maintenance. We conclude that monotherapy with thalidomide might be an alternative maintenance strategy with limited response duration for patients with primary PCL in impaired general condition.