Light Scatter	CD45/14	CD5/20

CD3/DR	CD45/38	CD138/19

CD40/56	CD19/Kappa	CD19/Lambda

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Explaination and interpretation of Flow cytometry results
Explaination of other results seen ( hematology,etc) and facts about this patient's disease

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CBC
WBC Differential
Bone marrow – characteristics/hematology

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• The bone marrow light scatter demonstrates a broad range of cell sizes present, ranging from small to large by light scatter properties. The small cells to intermediate cells are erythroid precursors by glycophorin A positivity and lymphocytes(data not shown). The intermediate to large sized cells are the largest single population (in numbers) in the bone marrow. This is the population which is shown gated and for which data is presented (see light scatter).

 
• The CD45/14 contour plot reveals that the majority of cells within the set light scatter gates are high intensity CD45 positive (a characteristic of lymphocytes. There are no monocytes/promonocytes present (see CD45/14).

 
• The CD5/20 contour plot reveals that virtually no cells within the gates express CD20 (B cell) or CD5 (Tcell). Therefore these cells are not classic T or B cells (see CD5/20).

 
• The DR/CD3 contour plot again confirms the lack of T cells (CD3 - T cell receptor) and B cells (B cells normally express HLA-DR). (see DR/CD3).

 
• The CD45/38 contour plot is quite revealing and gives us our first suggestion as to the cell's identity. CD38 is found on activated T and B cells (we know they are not T or B cells),  precursor cells & granulocytes (these can be excluded since they express dim CD45 and these cells express bright CD45), monocytes (these have already been excluded), NK cells, and plasma cells. This narrows the field to plasma cells and NK cells. If they are plasma cells they would be immature plasma cells since mature plasma cells do not express CD45 (see CD45/38). The clinical picture does not support an NK cell leukemia, but is consistent with that expected for a plasma cell lymphoproliferative disease.

 
• The CD138/19 plot confirms the suspicion that the cells are plasma/plasmacytoid cells since CD138 is positive.  CD19 was negative as well as CD20 (see CD5/20) which is the results expected for plasma cells (see CD138/19).

 
• Finally the clonal nature of the cell is demonstrated by the CD19/kappa and CD19/lambda contour plots where the majority of cells are CD19 negative but low intensity kappa positive.  Lamda expression was negative.  Normally, plasma cells do not express surface immunoglobulin, however, less mature plasma cells can (see CD19/Kappa, CD19/lambda).

 
• All of these results when taken together make the diagnosis of an unusual myeloma which is made by the lytic bone lesions together with the clonal population of plasmacytoid cells. It is unusual in the fact that most myelomas are caused by mature plasma cells which is not the case here.  This was confirmed by the fact that no monoclonal protein was found in the serum. The histology also demonstrates plasmacytoid/lymphoid cells (the clonal population) and only a very few mature plasma cells (which are not the tumor).