In our case, the lesion demonstrated strong CD138 and MUM1 positivity, lambda light chain restriction, a high Ki-67 proliferation index (>80%), and negativity for CD20, CD19, and EBER-ISH; findings consistent with a plasmablastic plasmacytoma rather than lymphoma or carcinoma [1,2,7,8]. This evidence concerns the gene MKI67 and plasmacytoma.