Background: The aim of the study was to improve the understanding of complex karyotype acute mixed cell leukemia containing pseudo Chediak-Higashi granules.
Methods: A case of acute mixed cell leukemia resembling AML1-ETO positive acute myeloid leukemia was reported. The results of morphological, immunophenotypic, and cytogenetic tests were analyzed by reviewing relevant literature.
Results: The patient was a young boy with clinical manifestations of recurrent fever. Bone marrow smear: Granulocyte system hyperplasia is obvious, visible at each stage, primitive cells account for 12%. These cells are large in volume, mostly round or class round, with abundant cell mass, stained gray blue, unbalanced development of some nuclear plasma, abnormal cytoplasmic staining, and visible "sunrise red" -like changes. Typical Auer bodies, pseudo Chadiak-Higashi granules and phagocytic erythroid substances were observed. The nuclei are irregular in shape, distorted and depressed, with fine chromatin and prominent large nucleoli. Bone marrow was extracted 3 days later, the bone marrow smear showed 65% primitive cells. The morphology of primitive cells was similar to that of 3 days ago. The results of flow cytometry showed that the primary/naive T cells in the samples possessed nuclear cells. Flow cytometry showed two groups of abnormal cells. One group accounted for 3.87% of nuclear cells and was a primitive/naive T-cell phenotype, mainly expressing: CD34+, CD7+, CD5+, CD2dim+, MPO-, CCD3 + part, CD3-, CD4-, CD8 -, CD117 -, CD13-, CD33-, HLA - DR -, CD10-, CD11b-, CD56-. The other group which accounted for 79.8% of the nuclear cells was monocyte phenotype, mainly expressing: CD34-, CD117-, CD13+ small amount, CD33+, HLA-DR-, CD11b+, CD14+, CD15+, CD36+, CD56+, CD64+, CD4+, CD85J+, CD85K + part. It matched the immunophenotype of acute mixed cell leukemia (T/MMPAL). Immunophenotypic leukemia-related fusion genes were negative, and karyotype analysis results were 45, XY, T (11; 12)(p13; Q13), -12-17, + mar /90 < n > 4, idem x 2 /46, XY. Combined with the above results, acute mixed cell leukemia was diagnosed.
Conclusions: The flow cytometry is the gold standard in the diagnosis of acute mixed cell leukemia. The diagnosis of acute mixed cell leukemia requires the combination of clinical manifestations, cellular morphology, immunology, cytogenetics and molecular biology, and the comprehensive diagnosis efficiency is obviously better than that of morphology.