Prolonged bone marrow failure with monosomy 7 after engraftment failure following bone marrow transplantation

A patient with acute myelogenous leukemia developed prolonged bone marrow failure along with the monosomy 7 chromosome abnormality. The patient had undergone bone marrow transplantation with CD34+ selection following induction failure. However, she then suffered engraftment failure and long-term pancytopenia. Her white blood cell count gradually increased with supportive therapy including granulocyte colony-stimulating factor (G-CSF), and chromosomal analysis of bone marrow cells revealed an abnormal karyotype. Thirty months after the bone marrow transplantation we observed monosomy 7 together with the existing chromosomal abnormality in the patient's bone marrow cells. It has been reported that some patients with idiopathic and posthepatitis aplastic anemia develop clonal disorders such as myelodysplastic syndrome/acute myelogenous leukemia with monosomy 7. The findings in our case suggest that the appearance of monosomy 7 in patients with aplastic anemia may be caused by prolonged low-level hematopoiesis, with or without G-CSF stimulation.