Objectives: To study the hematologic and immunophenotypic profile of 260 cases of acute myeloid leukemia at diagnosis.
Material and methods: This is a retrospective analysis of 260 cases of AML diagnosed at our institution between 1998 and 2000. Diagnosis was based on peripheral blood and bone marrow examination for morphology cytochemistry and immunophenotypic studies. SPSS software package, version 10, was used for statistical analysis.
Results: Seventy-six percent of our cases were adults. The age of the patients ranged from one year to 78 years with a median age of 27.2 years. There were 187 males and 73 females. The commonest FAB subtype, in both children and adults, was AML-M2. The highest WBC counts were seen in AML-M1 and the lowest in AML-M3 (10-97 x 10(9)/L, mean 53.8 x 10(9)/L). The mean values and range for hemoglobin was 6.8 gm/l (1.8 gm/l to 9.2 gm/l), platelet count 63.3 x 10(9)/L (32-83 x 10(9)/L), peripheral blood blasts 41.4% (5 to 77%) and bone marrow blasts 57.6% (34-96%). Myeloperoxidase positivity was highest in the M1, M2 and M3 subtypes. CD13 and CD33 were the most useful markers in the diagnosis of AML. CD14 and CD36 were most often seen in monocytic (38%) and myelomonocytic (44%) leukemias. Lymphoid antigen expression was seen in 15% of cases. CD7 expression was the commonest (11%).
Conclusion: AML accounted for 39.8% of all acute leukemias at this institution. The most common subtype was AML-M2. Myeloperoxidase stain was a useful tool in the diagnosis of myeloid leukemias. CD13 and CD33 were the most diagnostic myeloid markers.