Bone marrow aspirate smears and clot section showed a predominance of dyscohesive, large epithelioid cells with plasmacytoid appearance, prominent nucleoli, binucleation, and variably prominent cytoplasmic vacuoles (A and B, Wright stain of aspirate smears, 500X and 1000X respectively, and C, hematoxylin and eosin stain of clot section, 400X). The cells were positive for SOX10 (D, clot section immunohistochemistry [IHC], 400X) and negative for CD138 (E, clot section IHC, 400X). The cells were additionally positive for CD10 and CD117 (F, left side, clot section IHC, 400X). On flow cytometry, a distinct population was seen in the CD45 negative/high side scatter area; these cells were positive for CD117 and CD10 (F, right side, flow cytometry plots). A flow cytometry panel for plasma cells revealed polytypic plasma cells without immunophenotypic aberrancies.