Poster Presentation Australasian Cytometry Society 44th Annual Conference and Workshop

The importance of flow cytometry in identifying concomitant plasma cell myeloma and monoclonal B lymphocytosis- a case study (24546)

Esther Aklilu 1 , Selina Chen 1 , Joy Ho 1
  1. Royal Prince Alfred Hospital, Camperdown, NSW, Australia

Background:

The concomitancy of plasma cell myeloma (PCM) with another B-cell lymphoproliferative disorder (B-LPD) is rare [1]. There are reports of both simultaneous and sequential diagnosis of PCM and LPDs, with most reports describing PCM and chronic lymphocytic leukaemia [2,3]. This case study demonstrates the importance of flow cytometric immunophenotyping in identifying this rare phenomenon, particularly in cases of overt disease.

Case presentation:

A 75-year-old female experiencing bone pain and lethargy for 6-8 weeks was found to have a monoclonal IgG Kappa Paraprotein. Laboratory examination revealed anaemia (Haemoglobin: 109g/L, red cell count: 3.34x1012/L) with a mild lymphocytosis (3.1x109/L). Her total protein (104g/L), IgG levels (50.1g/L) and serum free kappa light chain (855mg/L) were markedly elevated.

Morphological analysis of the bone marrow (BM) aspirate and trephine revealed a hypercellular marrow with a marked plasmacytosis (70% of the total cells) and abnormal plasma cell morphology.

Flow cytometric immunophenotyping confirmed the presence of a Kappa light chain restricted plasma cell population with the phenotype CD38+ CD117(partial) CD138+ CD200+, consistent with PCM. In addition, analysis of the lymphocyte region demonstrated a simultaneous monotypic B cell population which was CD5(low) CD19+ CD20(low) CD22+ CD23+ CD200+ and Lambda light chain restricted. In conjunction with peripheral blood findings these results were consistent with monoclonal B lymphocytosis (MBL).

Conclusion

This is a rare case of concomitant PCM and MBL at diagnosis. This case highlights the importance of flow cytometric analysis in identifying and characterising multiple abnormal populations in a single sample, especially in cases where overt disease, in this case PCM, may conceal a concurrent low grade LPD. It is crucial that both abnormalities are identified as this would guide treatment considerations for patients.

  1. 1. Hasskarl J, Ihorst G, De Pasquale D, Schröttner P, Zerweck A, Wäsch R, Engelhardt M. Association of multiple myeloma with different neoplasms: systematic analysis in consecutive patients with myeloma. Leuk Lymphoma. 2011 Feb;52(2):247-59.
  2. 2. Christopher L. Alley, Endi Wang, Cherie H. Dunphy, Jerald Z. Gong, Chuanyi M. Lu, Elizabeth L. Boswell, James Burchette, Anand S. Lagoo; Diagnostic and Clinical Considerations in Concomitant Bone Marrow Involvement by Plasma Cell Myeloma and Chronic Lymphocytic Leukemia/Monoclonal B-Cell Lymphocytosis: A Series of 15 Cases and Review of Literature. Arch Pathol Lab Med 1 2013 April; 137 (4): 503–517.
  3. 3. Pereira WO, Bacal NS, Correia RP, Kanayama RH, Veloso ED, Borri D, Hamerschlak N, Campregher PV. Development of plasma cell myeloma in a B-cell chronic lymphocytic leukemia patient with chromosome 12 trisomy. BMC Res Notes. 2013 Oct 29;6:433.