AML M4Eo FAB - Bone marrow analysis

Author(s): S. Fruehauf, A. Pitkus
Institution(s): Heidelberg University Medical Centre
Last change of this image collection: 2004/08/19

Remark: An initial bone marrow was sent elsewhere and the biopsy results indicated a clear expansion of granulopoiesis with slightly reduced erythropoiesis and somewhat reduced megakaryopoiesis. Promyelocytic cells are noted as well as an increase in eosinophil precursor cells.

Immunophenotyping: Immunochemical staining is necessary to differentiate between regenerative bone marrow changes and a promyelocytic leukemia. In addition it is recommended that a peripheral blood specimen be sent for cytogenetics analysis to look for the t(15;17) translocation that is typical for a promyelocytic leukemia. This specimen shows no evidence of an infiltration by a malignant lymphoma.

Comment on this image collection: The first bone marrow performed at our institution was on day 15 of chemotherapy due to an earlier specimen being a dry tap. The bone marrow specimen is hypercellular for a patient of this age. Megakaryopoiesis and erythropoiesis are sufficient, while the granulopoesis reveals mainly mature cells, but with an increase in the eosinophilic population, consisting of 50% of the cells. There is also an increase of blasts seen in 30% of the total cells. Morphologically the findings are indicative of an acute leukemia, most likely an acute myeloid leukemia of the M4 Eo subtype. One is also referred to the immunophenotyping and molecular genetic findings.

Differential diagnosis: Acute promyelocytic leukemia

Low power microscopy