The role of adhesion molecules in the physiopathology of multiple myeloma has been the target of many studies over the last years. The CD56 expression by neoplastic plasma cells is related to a less aggressive clinical course, and its loss is described in plasma cell leukemia. The evaluation of the CD56 expression may be obtained by flow cytometry, with positivity in 55% to 78% of cases. In this study, we verified the CD56 expression by plasma cells in bone marrow of myeloma patients using immunohistochemistry in samples obtained at diagnosis. We analyzed bone marrow of 20 myeloma patients and performed immunohistochemistry to determine the expression of the kappa and lambda light chains and CD56 by neoplastic plasma cells. The CD56 expression was important in three samples, moderate in six, discrete in four and negative in seven. Immunohistochemistry was valid to determinate CD56 expression by neoplastic plasma cells in myeloma patients, giving similar results when compared with flow cytometry. It was possible to evaluate the variations in the CD 56 expression using this method.
Multiple myeloma; CD56; adhesion molecule; immunohistochemistry
