AML with multilineage dysplasia
AML with myelodysplasia-related changes is a sub-entity of AML that has a poor prognosis. It is characterized by a history of MDS, significant morphologic dysplasia, or MDS-related cytogenetic features such as -7/del(7q) and others. 20%+ blasts in peripheral blood or bone marrow and (a) prior diagnosis of MDS or MDS/MPN; (b) cytogenetic abnormalities associated with MDS or (c) multilineage dysplasia in > 50% of the cells of at least 2 separate bone marrow lineages
immunophenotype of blasts exhibits similar characteristics as seen in MDS. Antigens associated with myeloid differentiation, such as MPO, CD33, CD13, CD64, CD14 and CD15 are seen in various degrees. MDS related AMLs with monocytic differentiation also show expression of CD45 and lack CD34. Additionally, the aberrant expression of CD10, CD56 and CD7 in blasts may be found . AML-MRC cases associated with monosomy 5 or 7 may show aberrant expression of TDT and CD7.