AML M4Eo FAB: Acute myelomonocytic leukemia with eosinophilia - 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 noticed some swelling on his or her right flank and wasn't feeling well, prompting a visit to his or her family doctor. A complete blood count (CBC) was performed and a leukocytosis was noted. The patient was admitted to our institution for further investigation of the symptoms. The symptoms now included increasing tiredness, weight loss, and nightsweats.

Clinical Examination: The initial leukocytosis was 33 /nl with 27% myeloid blasts circulating in the peripheral blood. A bone marrow analysis was performed revealing an infiltration of myeloid blasts comprising 70% of the cells and an infiltrate of atypical eosinophilic granulocytes comprising 10-20% of the cells. In addition, the patient had a hemoglobin of 8.0 g/dl and a thrombocytopenia of 40 /nl. The findings indicate a diagnosis of a secondary myeloid leukemia of the M4 Eosinophil subtype.

Laboratory results:

Parameter	Value	Normal Value [Unit]
RBC	2.3	4.0-5.2 /pl
Hemoglobin	8.3	12.-15. g/dl
Hematocrit	0.23	0.36-0.47 l/l
MCV	101	83-97 fl
Plt	33	150-440 /nl
WBC	33.93	4.0-10.0 /nl
Neutrophils	3.73	1.8-7.7 /nl
Lymphocytes	5.77	1.0-4.8 /nl
Monocytes	14.93	0.2-0.8 /nl
Eosinophils	0.34	0-0.5 /nl
Differential	Results
Band Neutrophils		3-10 %
Segmented Neutrophils	11	50-70 %
Lymphocytes	17	25-70 %
Atypical Lymphs		0 %
Monocytes	44	2-9 %
Eosinophils	1	2-4 %
Basophils		0-1 %
Metamyelocytes	1	0 %
Myelocytes		0 %
Promyelocytes		0 %
Blasts	26	0 %
Normoblasts		/ 100 L
Bone Marrow	Differential	Results
Red cell Precursors	10
Blasts	60
Promyelocytes	4
Myelocytes	2
Band Neutrophils	6
Segmented Neutrophils	4
Eosinophils	12
Basophils	4

Molecular genetics (incl. Southern blot, PCR): Molecular diagnostic testing was performed on a bone marrow specimen. The analysis of a control gene resulted in a good quality of the breakmaterial. In the available sample the CBFb-MYH11 Rearrangement (inv16) could be proven. The other AML typical changes, PML, RARA and AML 1ETO were not proven by means of PCR. Also a FLT3-ITD mutation could not be proven.

Diagnosis: Acute myeloid leukemia of the M4 Eo subtype

Differential diagnosis: See Immunophenotyping