Plasma cell leukemia - one in a million: A case report.

Background: Plasma cell leukemia (PCL) is diagnosed by the presence of an absolute plasma cell count of > 2 × 10/L or 20% plasma cells in the peripheral blood. Because the incidence of PCL is relatively low, our case report study presents a rare opportunity to describe the clinical and pathological characteristics of this leukemia, as well as different modalities of treatment and outcomes of primary PCL (pPCL).

Case Summary: A 56-year-old male with a history of hypertension complained of pain in the left flank area which started four months prior to admission. On admission, his vital signs were stable, and physical examination was completely benign. Laboratory evaluation showed hemoglobin of 5.1 g/dL, white blood cell count of 6.6 cells per cubic millimeter with 16% atypical lymphocytes, and platelet count of 51000 per microliter. Peripheral smear showed more than 10%-15% of plasma cells (Figure 1), and flow cytometry of peripheral blood confirmed PCL with 24% plasma cells CD138+. Bone marrow biopsy demonstrated 80% plasma cells (38+, 138+, 117+, 10-, 19-, 20-, 56-) with 90% cellularity. The Oncology team was consulted, and VCD therapy was started. After completing therapy at 1, 4, 8, and 11 d, the patient was discharged home. The patient was being considered for a bone marrow transplant evaluation within two months of discharge.

Conclusion: PCL is a rare and aggressive form of leukemia with a poor prognosis. Multi-center studies and clinical trials should be conducted to develop accurate criteria for the initial diagnosis and prompt treatment of this disease.