Myeloid neoplasms secondary to plasma cell myeloma: an intrinsic predisposition or therapy-related phenomenon? A clinicopathologic study of 41 cases and correlation of cytogenetic features with treatment regimens.

We describe 41 cases of myeloid neoplasms (MNs) secondary to plasma cell myeloma (PCM). The types of MN included myelodysplastic syndrome (MDS) in 34 (82.9%), acute myeloid leukemia (AML) in 4 (9.8%), and myeloproliferative neoplasm (MPN) or MDS/MPN in 3 (7.3%) cases. The latency from treatment to diagnosis of MN ranged from 9 to 384 months, with a median of 60 months. Of 37 cases with cytogenetic studies, complex abnormalities were detected in 22 (59.5%), –5(q)/– 7(q) in 4 (10.8%), other abnormalities in 8 (21.6%), and normal karyotype in 3 (8.1%) cases. Complex abnormalities and –5(q)/–7(q) correlated directly with multiple chemotherapeutic regimens, particularly with combined melphalan/cyclophosphamide. Moreover, the features of cytogenetic abnormalities in our series were significantly different from those with concomitant PCM/ MN who had significantly lower complex abnormalities. The latency, skewed proportion of MDS, and bias