RESUMEN
<p><b>OBJECTIVE</b>To identify the clinical and pathological features of acute myeloid leukemia with B lymphoproliferative disorders.</p><p><b>METHODS</b>The characteristics of 3 cases of acute monocytic leukemia with untreated chronic lymphocytic leukemia/monoclonal B-cell lymphocytosis were reported with literatures review.</p><p><b>RESULTS</b>The patients presented with a history of anemia, bleeding and/or fever. Acute monocytic leukemia was diagnosed by bone marrow morphology, cytochemistry and pathology studies. Immunophenotyping by flow cytometry analysis showed a significant population of absolute B-lymphocyte count of > 5×10(9)/L in a patients, similar to that of chronic lymphocytic leukemia.</p><p><b>CONCLUSIONS</b>The association of acute monocytic leukemia and untreated chronic lymphocytic leukemia/monoclonal B-cell lymphocytosis was a rare event. The abnormal B lymphocytes was likely to be misdiagnosis. Thus, it was important to combine several kinds of laboratory studies, especially flow cytometry to identify this rare disorder.</p>