BRIEF COMMUNICATION Myelodysplasia during the course of myeloma. Restriction of 17p deletion and p53 overexpression to myeloid cells

We report a case of myelodysplastic syndrome (MDS) occurring during the course of multiple myeloma (MM) treated by alkylating agents. Karyotype showed unbalanced t(5;17), resulting in 17p deletion. Dysgranulopoi esis typical of the ‘17p− syndrome’ and p53 mutation and overexpression were present. A combination of FISH and immunophenotype analysis (FICTION, analysis) showed that 17p deletion was restricted to myeloid cells, and that p53 overexpression was also restricted to myeloid cells. These findings strongly argue against a common clonal origin of MM and MDS, and support the hypothesis that MM and MDS were clonally unrelated, and that MDS was indeed secondary to treatment with alkylating agents.