Myeloid sarcoma is a rare manifestation of AML and can appear concomitantly with, following or rarely antedating the onset of bone marrow leukemia [1]. MS can be the sole manifest of AML relapse after allo-SCT. We describe two patients presenting with myeloid sarcoma as the only sign of AML relapse after allo-SCT. We discuss diagnostic and therapeutic aspects of this assumed rare manifestation of relapse after allo-SCT.

۲٫ Patients

۲٫۱٫ Patient 1. ,e patient was a 40-year-old Asian female diagnosed with AML during pregnancy (Figure 1). ,e bone marrow examination then showed 90% myeloblasts, with immunophenotype CD45dim/117+/13dim/33+/56−/۲−/۱۵−/ ۱۴−/۱۱b−/۹۹+/HLA-DR−; CD34 positivity was detected for a subpopulation of 8% of blasts. Karyotyping showed t(7;11) as the only cytogenetic abnormality; this translocation between chromosomes 7p15 and 11p15 involved the NUP98 gene on chromosome 11. Medical termination was performed before she received conventional induction therapy with daunorubicin 50 mg/m2 once daily on days 1–۳ and cytarabine 200 mg/m2 as daily continuous infusion on days 1–۷, and she reached complete hematological remission after this single induction cycle. ,is treatment was followed by consolidation therapy with 4 cycles of high-dose cytarabine, each of these cycles consisting of cytarabine 3 g/m2 twice daily on days 1, 3, and 5. Relapsed disease was diagnosed 24 months after the rst treatment was completed; at the time of relapse, she was pregnant in the 28th week and she was induced for labor in the 29th week. Cytogenetic analysis detected the original t(7;11) translocation in 6 out of 14 metaphases, and additional t(12;17) with a translocation between chromosome 12p11 and 17q11 was also detected together with loss of the derivative chromosome 17.€e latter abnormality leads to the loss of genes on 17p including the p53 gene. €e immunophenotypic features were similar as at initial diagnosis. New induction treatment was performed by idarubicin 12 mg/m2 once daily on days 1–۳ and cytarabine 200 mg/m2 as daily continuous infusion on days 1–۷, and again she reached complete hematological remission after one induction cycle. €en she was given further consolidation therapy with one cycle of amsakrin 150 mg/m2 once daily on days 1–۵, etoposide 110 mg/m2 once daily on days 1–۵, and cytarabine 200 mg/m2 as daily continuous infusion on days 1–۵٫ After this, she proceeded to myeloablative conditioning (MAC) allo-SCT with a matched sibling donor. She showed no sign of GVHD at any time after the transplantation, and she achieved full donor chimerism.