Plasma Cell Leukemia-Behind a Disguise

Plasma cell leukemia is a variant form of multiple myeloma with its own unique form of presentation. It may have a presentation resembling a lymphoproliferative disorder which if not investigated in detail can lead to misdiagnosis and thus completely different line of investigation. Our patient presented to us with disturbed dietary regimen, significant weight loss and was a known case of hypothyroidism since 2009 for which he was on medications. At the other centre, complete blood picture showed bicytopenia with hyperleucocytosis while bone marrow biopsy performed showed a diagnosis of lymphoproliferative disorder with a morphological diagnosis of Hairy cell leukemia. At our center, his complete blood count showed bicytopenia with leucocytosis as before but the morphological examination of his peripheral smear showed the presence of 80% plasma cells. The immunophenotyping showed CD23(+) and CD56(+) while the immunohistochemistry showed CD23(+), CD56(+) and CD138(+). Cytogenetics showed the presence of t(4;14) in 5% of the cells examined. Based on the above mentioned investigations, a diagnosis of Plasma cell leukemia was reached and the patient was placed on a treatment regimen including Lenalidomide, Bortezumib and Dexamenthasone. His blood counts came within the normal range within a week of starting the treatment. Bone marrow biopsy accounts for one of the many steps that should be taken to reach a correct diagnosis. Keeping in mind the variable presentation a disease can show, as many investigative tools should be undertaken as is clinically and economically possible for reaching at a correct diagnosis and thus the decision of the eventual treatment plan for the patient.