Biclonal post-transplant B-cell lymphoma: report of a case with two distinct cell populations, XX,t(14;18) and XY,t(11;14).

Lymphoproliferative disorders are more likely to occur in transplant patients compared to the general population. Typically in these patients, lymphomas occur within 6-10 months following transplant and are Epstein-Barr virus (EBV) positive. We report a biclonal apparently EBV negative lymphoma occurring in a patient ten years after renal transplant, with karyotypes XX,t(14;18) and XY,t(11;14). Though the biclonal populations also had different sex chromosome compositions, complete evaluation showed that both clones most likely evolved from the patient's native lymphocytes.