Objective@#To describe the MICM (morphology,
immunology,
cytogenetics and
molecular biology) characteristics of a case of
acute myelomonocytic leukemia M 4C . @*
Methods@#The medical
history data of the case of M 4C admitted to our
hospital was reviewed. The results of
bone marrow cell morphology, cytochemical
stains,
bone marrow biopsy, immunophenotype,
cytogenetics, molecular test and NGS (
next-generation sequencing) of the case were analyzed. @*Results@#The
bone marrow smear showed markedly active proliferation of
bone marrow cells in which the myelomonocytic
cells accounted for 85.6%. Cytochemical
stains showed
peroxidase (POX)
stain partially and weakly positive; specific
esterase AS-DCE partially positive;
non-specific esterase α-NBE partially positive and smothered by
sodium fluoride;
non-specific esterase AS-DAE partially positive and smothered by
sodium fluoride.
Bone marrow biopsy showed hyperproliferative
cells and diffused
hyperplasia of blasts. Immunophenotype
analysis showed that the abnormal
cell population was positive for CD11B, CD64, CD56, cMPO, CD33, CD41, CD61, CD38 and CD58, but negative for CD13, CD34, CD117, CD7, CD123,
HLA-DR, CD10, CD19, CD20, CD2, CD14, CD235, CD15, CD303, CD304, CD25, cCD79a, cCD3, cCD22, CD1a and TDT.
Cytogenetic analysis showed 47, XY, t(9;11) (p22;q23),+mar. The molecular test for
leukemia showed MLLT3/KMT2A
gene rearrangement. NGS showed NRAS and TET2
mutation. The case was finally diagnosed as AML (
acute myelomonocytic leukemia) M 4C with t(9;11)(p22;q23), MLLT3-KMT2A. @*Conclusion@#
Leukemia M 4C may show the characteristics of both
granulocytes and
monocytes with complex morphological features. The combined examination of MICM should be necessary for the
diagnosis of M 4C with great significance.