AML M2 FAB: Acute myeloblastic leukemia with maturation - case report 2

Author(s): S. Fruehauf, A. Pitkus, J. Dengler, S. Kraeker
Last change: 2003/04/10

Medical history: The patient has a history of foot abscesses and presented with a fever, new hematoma, and suspected pneumonia.

Clinical Examination: Upon initial presentation the patient was foudn to have a leukocytosis of 52 /nl with 81% blasts in the peripheral blood as indicated by the complete blood count (CBC) results below. Ímmunophenotyping of the bone marrow was performed 4 days later and bone marrow morphology was performed 2 weeks later to further investigate these abnormal results.

Laboratory results:

Parameter	Value	Normal value [unit]
RBC	1.9	4.0-5.2 /pl
Hemoglobin	5.8	12.-15. g/dl
Hematocrit	0.17	0.36-0.47 l/l
MCV	88	83-97 fl
Plt	49	150-440 /nl
WBC	49.63	4.0-10.0 /nl
Neutrophils	1.99	1.8-7.7 /nl
Monocytes		0.2-0.8 /nl
Lymphocytes	6.95	1.0-4.8 /nl
Eosinophils		0-0.5 /nl
Differential	Results
Band Neutrophils	1	3-10 %
Segmented Neutrophils	3	50-70 %
Lymphocytes	14	25-40 %
Atypical Lymphs
Monocytes		2- 9 %
Eosinophils		2-4 %
Basophils		0-1 %
Metamyelocytes		%
Metamyelocytes		%
Promyelocytes	1	0 %
Blasts	81	0 %
Normoblasts		/ 100 L

Cytogenetics: From the bone marrow cultures, there are 5 analyzable Metaphases, which were completely karyotyped. It was found that each showed a Translocation between chromosomes 8 and 21, with breakpoints at q22 in each case. This translocation is an indicator of a good prognosis for the patient.

Molecular genetics (incl. Southern blot, PCR): The analysis of a control gene resulted in a good quality of the sample material. 2 FLT 3-ITD mutations with a surface relationship of wt=1,2 could be proven.

Other molecular diagnostics: These mutations were shown in the AML-96 study to be increased risk along with these laboratory findings: leucocytosis of 52 /nl, 81% blasts in the peripheral blood, 60% blasts in the bone marrow, cytogenetic translocation of t(8;21) and FLTD3-ITD mutation relationship: wt=1,2.

Diagnosis: Acute Myeloid Leukemia of the M2 subtype

Differential diagnosis: Acute myeloid leukemia with recurrent genetic abnormalities of the t(8:21)(q22;q22); (AML1/ETO) subtype