Dysmorphic plasma cells in multiple myeloma

A 50-year-old-woman, a known case of plasmacytoma of right clavicle, was admitted for further evaluation. Laboratory investigations revealed bicytopenia (hemoglobin: 11 g/dL, platelet: 88 × 103/µL), erythrocyte sedimentation rate: 72 mm, serum calcium: 8.78 mg/dL, urea: 19 mg/dL, creatinine: 0.75 mg/dL, total serum protein: 7.8 g/dL, serum albumin: 4.1 g/dL, serum globulin: 3.7 g/dL, and beta-2 microglobulin: 3190 ng/mL. Peripheral blood smear showed marked rouleaux formation [Figure 1a] with no atypical cells/blast. Bone marrow aspiration showed plasmacytosis (20%) predominantly of mature plasma cells. Some of these plasma cells demonstrated pleomorphic morphology, resembling immature megakaryocyte [Figure 1b], multinucleation [Figure 1c], and nuclear budding and multilobulation [Figure 1d and e], suggestive of the anaplastic variant of myeloma. Immunohistochemistry done on trephine biopsy showed diffuse strong membranous staining for CD138 [Figure 2a and b].Figure 1: (a) PS with marked rouleaux formation. BMA smears (MGG, 100×) with (b) dysmorphic plasma cells (c-e) multinucleation, budding, and lobulationFigure 2: (a) Bone marrow trephine showing pleomorphic plasma cells (H&E, 40×) and (b). Diffuse membranous staining with CD138Serum protein electrophoresis showed an increase and a spike pattern of beta globulin (0.62 g/dL) and gamma globulin (2.29 g/dL), with normal alpha 1 and 2 globulins. Two distinct bands (band 1: 0.40 g/dL, band 2: 0.85 g/dL) were seen in the gamma region. Band 1 corresponds with immunoglobulin A (IgA) and kappa, while band 2 corresponds with IgG and kappa [Figure 3a] suggestive of biclonal gammopathy. By nephelometry technique, serum IgG was high (21.5 g/L), IgA was high (13.8 g/L), and IgM was normal (0.44 g/L). Immunofixation studies revealed a biclonal IgG and IgA kappa band [Figure 3b]. Turbidimetric technique measurement of kappa/lambda free light chain revealed high free kappa light chain (285.40 mg/L) and normal free lambda light chain (21.82 mg/L).Figure 3: (a) Protein electrophoresis with two peaks in the gamma globulin region (b) Immunofixation shows IgG kappa and IgA kappa gammopathyAnaplastic multiple myeloma (AMM) is a distinct, rare variant of multiple myeloma which is aggressive and treatment-resistant.[1,2] It has a predilection for extramedullary sites and an association with the IgA isotype.[2] The simultaneous occurrence of two distinct M bands is termed “biclonal gammopathy” and is seen in 2%–6% of multiple myeloma cases.[3] To our knowledge, there are no case reports of anaplastic myeloma with biclonal gammopathy. Myeloma FISH and P53 status were not performed in this patient because of financial constraints. P53 positivity carries poor prognosis and might change the management of the patient with a four-drug regimen including monoclonal antibodies instead of the standard three-drug regimen. The pleomorphic plasma cells present in the anaplastic variant can be mistaken for cells from poorly differentiated carcinoma or even megakaryocytes.[2] Hence, it is important for the pathologist to be aware of this morphology against the appropriate clinical background. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.