Synchronous development of acute myeloid leukemia in recipient and donor after allogeneic bone marrow transplantation: report of a case with comments on donor evaluation

A case of donor cell leukemia (DCL) is reported. A 42-year-old female developed acute myeloid leukemia (AML) of donor cell origin 18 months after a bone marrow transplant (BMT) from her brother. At the time DCL presented, the donor-brother was also diagnosed with AML showing identical cytogenetic abnormalities. The classification of DCL and recommendations for laboratory testing of potential hematopoietic stem cell (HSC) donors are discussed. Marrow specimens were obtained from the posterior iliac crest and analyzed using standard techniques. Leukemic cells were analyzed by flow cytometry. Karyotyping and fluorescence in situ hybridization were performed using standard methods. The recipient-sister's original diagnosis was erythroleukemia. Chromosome analysis showed a 46,XX,t(3;5)(q25;q34) karyotype. Both the recipient's new AML and the donor's AML showed an identical karyotype: 46,XY,inv(3)(q21q26),-7. Both patients were resistant to therapy and died. The clinical and biological aspects of DCL are discussed including the distinction between transformation of healthy donor cells to leukemic cells and transmission of preformed leukemic cells. The former represents almost all the reported cases of DCL compared with transmission of leukemic cells from donor to recipient. With an aging donor population, it is estimated that the latter will increase. Increased testing of older donors to include routine morphologic study of blood and marrow, cytogenetic studies, and evaluation for clonal lymphoproliferative disorders is recommended.