abnormal bone marrow hematopoietic cell morphology +
abnormal common lymphocyte progenitor cell morphology +
abnormal common myeloid progenitor cell morphology +
any structural anomaly of the hematopoietic stem cells that are capable of forming any of the myeloid lineage cells (erythrocytes, granulocytes, thrombocytes, monocytes, and mast cells) but not cells of the lymphoid lineage