Multiple Myeloma with Foamy Mott Cells

Figure 1

Bone marrow biopsy with foamy Mott cells on (a) H&E immunostain for (b) CD68 highlights scattered smaller cells of macrophage-monocyte lineage, but are negative in the larger foamy cells; however, they are positive for (c) CD138 and (d) kappa, confirming their plasmacytic differentiation. Note that the cytoplasmatic kappa IHC pattern matches the inclusions seen on H&E. (e) Bone marrow aspirate smear (Wright stain). (f) Posttherapy bone marrow biopsy, lambda light chain. Trephine biopsy cells original magnification 200x; aspirate smear (cell (E)) original magnification 1000x.

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