Normal hematopoietic function and multiple bone marrow clonal abnormalities in a patient with acute myeloid leukemia after two mismatched stem-cell transplants with graft failure and autologous reconstitution

A 13-year-old male with primary refractory acute myelogenous leukemia (AML-M0), underwent two mis matched stem cell transplantations (SCT) and experienced graft failure after both procedures. Of interest, his peripheral blood cell counts are normal 7 years after his first SCT, his bone marrow is morphologically normal, however, cytogenetic analysis reveals multiple recurring cytogenetic abnormalities. This is the third case of chromosomal instability with morphological normal marrow and peripheral blood to be reported, these rare cases suggest that hematopoietic stem cells must have compensating mechanisms that allow normal function despite extensive chromosomal damage, supporting the notion that normal marrow func tion is possible even with extensive chromosomal damage.