RESUMO
We are presenting a case of an adult male patient with monocytic acute myeloid leukemia (AML) who had on presentation brain infarction and bilobed nuclei had been demonstrated in many of the leukemic blasts. There was no laboratory evidence of acute disseminated intravascular coagulopathy, on presentation or later on. Initially the diagnosis of acute promyelocytic leukemia (APL) was considered, so all trans-retinoic acid (ATRA) was added to induction chemo therapy. As the diagnosis of APL was ruled out, based on the flow cytometry, fluorescent in situ hybridization and polymerase chain reaction findings, the ATRA was discontinued and the patient continued on the standard AML chemo therapy induction regimen. Later on chromosomal analysis was also normal. Sever dehydration on presentation, would have contributed to brain infarction. AML particularly monocytic, can mimic APL, especially its microgranular variant. The possible ATRA therapy side effects, can be avoided by early confirmation of the diagnosis.