Chronic lymphocytic leukemia complicated by plasmacytoma originating from different clones

In a woman with chronic lymphocytic leukemia (CLL), a plasmacytoma develope d on the back region after four years. CLL cases complicated with plasmacyt oma are rare. In the present case, the plasmacytoma showed kappa cytoplasmi c immunoglobulin (Ig), and the CLL showed gamma lambda surface I,a. To reve al the clonal origin of CLL and plasmacytoma, we analyzed Ig gene rearrange ments in the patient's peripheral blood and plasmacytoma. Ig gene DNA analy sis confirmed the presence of different rearrangements in the heavy and lig ht chain genes of CLL and plasmacytoma. These findings suggest that in this patient, the two B cell malignancies arose from expansion of two phenotypi cally and genotypically distinct clones.