Multiple myeloma is a malignant disease caused by unregulated proliferation of mature plasma cells. Very few cases present as blast cells in the bone marrow with intense basophylic cytoplasm and monocytoid morphology, suggesting acute leukemia. This paper presents immonophenotypying in 2 cases with the diagnostic hypoteses of myelomonocytic myeloma, showing the simultaneous expression of plasmocytic, myelomonocytic and T cell antigens. Immonophenotypying was done in peripheral blood and bone marrow with classical techniques, using the following monoclonal antibodies: CD2, CD3, CD4, CD5, CD7, CD10, CD19, CD20, CD25, CD33, CD34, CD38, CD41, CD45, CD56, CD71, HLA-DR, TCR alpha/beta, DCR gama/delta, kappa, lambda, surface IGM and IGG, intracitoplasmic kappa, lambda, IGM and IGD, MPO, CD79a and intracitoplasmic CD3. Morphology was evaluated with pan-chromatic Romanovsky stain and cytochemical stains - PAS, peroxidase, Sudan Black B, alpha-naphtil acetate esterase and Oil Red O. Cytogenetic analysis was done with banding techniques and FISH. Clonal cytogenetic alterations were present in both cases, one with chromosomo 8 trysomy and the other with long arm delection of chromosome 7 and short arm delection of chromosome 6. The percentage positivity of specific markers were clean cut making the diagnosis clear.
Multiple myeloma; Morphologic analysis; Cytogenetic analysis; Flow cytometry
