Aggressive course of primary plasma cell leukemia with unusual morphological and cytogenetic features

A case of aggressive plasma cell leukemia with unusual morphological and cytogenetic features is reported. A 65-year-old man was admitted to hospital due to anemia, thrombocytopenia, and renal insufficiency. Bone marrow examination and peripheral blood smear revealed a large number of pleomorphic cells with convoluted and multilobulated nuclei. Immunohistochemistry of the bone marrow biopsy was negative for anti-keratin antibodies CAM.5.2 and AE1/AE3, but positive for EMA. The immunophenotypic features of these cells were suggestive of plasma cell origin with positivity for CD38, CD56, CD9, and CD44 and a weak positivity for CD71 and CD45 (40% of the cells), while all other markers of hematopoietic origin were negative. Furthermore, a serum protein electrophoresis showed a monoclonal component type IgG-kappa of 70 g/l. The cytogenetic analysis demonstrated a hypotetraploid clone with multiple numerical and structural abnormalities. Although some of the aberrations found are associated with plasma cell malignancies--e.g., structural rearrangement of chromosome 1, del(6q), and monosomy 13--the karyotypic complexity in the present case is unusual. The course of the disease was very aggressive, and the patient died 3 days after admission.