AML M1 FAB: Acute myeloblastic leukaemia (immature) - case report 1

Author(s): S. Fruehauf, A. Pitkus
Last change: 2004/08/19

Sort of case report: In clinical view

Medical history: The patient presented to another institution with complaints of epigastric pain and left flank pain for about 6 months. Upon further investigation, no fever or infectious cause was found. However, the complete blood count (CBC) revealed a leucocytosis of 56 /nl with blasts present in the peripheral blood. The initial bone marrow analysis performed at the outside institution indicated an infiltration of 90% of the total cells containing myeloid blasts. The resulting diagnosis was acute myeloid leukemia of the M1 subtype. The factors present at diagnosis placed the patient into a high risk situation prognostically. Therefore, the patient came to our clinic to participate in a study protocol.

Clinical Examination: The bone marrow cytology occured 15 days after chemotherapy. The accompanying complete blood count (CBC) is below.

Laboratory results:

Parameter	Value	Normal value [unit]
RBC	3.4	4.3-6.1 /pl
Hemoglobin	10.2	13.-17. g/dl
Hematocrit	0.30	0.38-0.52 l/l
MCV	88	83-97 fl
Plt	116	150-440 /nl
WBC	56.81	4.0-10.0 /nl
Neutrophils	1.14	1.8-7.7 /nl
Lymphocytes	0.57	1.0-4.8 /nl
Monocytes	1.14	0.2-0.8 /nl
Eosinophils	0.57	0-0.5 /nl
Differential	Results
Band Neutrophils		3-10 %
Segmented Neutrophils	2	50-70 %
Lymphocytes	1	25-40 %
Aytipical Lymphs		%
Monocytes	2	2-9 %
Eosinophils	1	2-4 %
Basophils		0-1 %
Metamyelocytes		%
Myelocytes		%
Promyelocytes		%
Blasts	94	0 %
Normoblasts	2	/ 100 L

Cytogenetics: Cytogenetic analysis at an outside institution revealed multiple chromosomal aberrrations with trisomy 13, 20, 21, and 2. Chromosome analysis after 48 hours of culture resulted in about 400 aberrations. The structurally inconspicuous male karyotype has a trisomy 13 in one analyzed mitosis, while in 18 analyzed phases a clone with numerous aberrations of a structurally inconspicuous male karyotype with trisomy 13, 20 and 21 was detected and in 6 analyzed phases a clone with trisomy 13, 21, and 22 was noted. Trisomy 13, 20, 21, and 22 are all suggestive of an acute myeloid leukemia.

Molecular genetics (incl. Southern blot, PCR): Molecular Diagnostics was performed by an outside instituion on a bone marrow specimen. The analysis control gene resulted in a good quality of the sample material. The probe tested the following observations which are associated with typical acute myeloid leukemia: AML-1-ETO; t(8;21); PML-RARA; t(15;71), and CBFb-MYH11. Inversion 16 by means of PCR was not proven, although a FLT3 mutation was demonstrated.

Diagnosis: Acute Myeloid Leukemia of the M1 subtype