细胞看起来不太象浆细胞瘤中的瘤细胞样。但细胞单一，还要考虑肿瘤。结合病史，要考虑或排除浆细胞瘤。

The tumor cells are not those seen in multiple myelomas/plasmacytomas. Instead, they have epithelial appearance with plump cytoplasm. If this is midline with destruction of underlying vertebral bone, I raise the possibility of chordoma. Please provide more information - age of the patient, where in the back is the current tumor, is it involving vertebral column in the midline, is the "myeloma" previously diagnosed at the same location, how long ago has the myeloma been diagnosed, was it ever treated by radiation, what was the clinical response to radiation therapy, etc.

 the interpretation of this case, to  my view, should be tumor, favoring the malignant nature, based on the following observations: 1: there are hypercellarity, 2: the cells are not the normal cells located on the back via the FNAC. 3: the nuclear dysplasia, including the different size, marked nucleoli, irregular  nuclear envelops. so the technique of cell block is an essential part to make a differential diagnosis.

 细胞形态单一，核仁明显，肿瘤性改变。结合病史，还是考虑浆细胞瘤。