Three Cases of Plasma Cell Leukemia

Introduction: Plasma cell leukemia (PL) is a rare lymphoproliferative disorder characterized by the monoclonal proliferation of plasma cells in the marrow and blood peripheral. It is defined by a blood plasmacytosis greater than 2 G/l or a plasma cell level greater than 20% of leukocytes. It can be primitive or secondary to multiple myeloma (MM). We reported 3 cases of PL. Observations: Case 1: A 59 years old woman with fever, anemia with 7 g/dl, hyperleukocytosis 9200/mm3, thrombopenia 86 G/l inflammatory biological syndrome with CRP at 129 mg/l, hypercalcemia at 120 mg/l, renal failure with serum creatinine at 35 mg/l, urea at 0.85 g/l and 24-hour proteinuria at 0.98 g/24h. Β2 microglobulin at 10.34 mg/l. The blood smear shows dysmorphic plasma cells at 68% and the bone marrow at 79% of dysmorphic plasma cells. The immunophenotyping of blood cells, the electrophoretic serum protein, shows PL CD38+, secondary of a MM LAMBDA. Case 2: A 65-year-old man with type 2 diabetes presented, right femoral neck, anemia, hyperleukocytosis at 22 G/l, and thrombocytopenia at 99 G/l. There was no hypercalcemia, or kidney failure. The blood smear showed 28% of plasma cells and 9% of blasts. On the myelogram, the marrow was normal richness with significant medullary plasmacytosis (31%) made up of dysmorphic plasma cells. The CT scan showed a settling of the body of D5 with heterogeneous osteocondensation. The patient was transferred to hematology where she was treated with polychemotherapy. The evolution was unfavorable following a death due to malignant hypercalcemia. Case 3: A 62-year-old woman who had a 5-year follow-up of Ig G kappa multiple myeloma was treated with Melphalan, Prednisone, and thalidomide with a therapeutic break for 2 months. She came back to the Internal Medicine department with: severe global dehydration, anemia with externalized bleeding gingivorrhagia, pain in mechanical bones of the ribs, lower limbs, and pelvis, bilateral pneumonia. The biology found hyperleukocytosis at 99 G/l, anemia at 4.7 g/dl, thrombocytopenia at 31 g/l, hypercalcemia at 190 mg/l, renal failure with creatinine at 34 mg/L, and urea at 1.08 g/l, a biological inflammatory syndrome with CRP 294 mg/l. The smeared blood had shown 93% blood plasma cells and immunophenotyping showed CD38+. The patient died before specific treatment for the disease. Conclusion: Plasma cell leukemia is a rare atypical variant, complicating essentially multiple light chain myeloma. She must be suspected especially when there are cytological abnormalities such as major leukocytosis or thrombocytopenia, which are unusual in classical myeloma. Evolution is usually a very bad prognosis, with a median survival of 12 to 14 months for the form primary and 2 to 3 months for the secondary form.