AML M4Eo FAB: Acute myelomonocytic leukemia with eosinophilia - case report 2

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

Sort of case report: In clinical view

Medical history: The patient was seen at another institution for fatigue, a decrease in weight, and a bloated abdomen. A gastroscopy was performed revealing a tumor. A sample of ascites fluid and tissue from this area were sent to pathology for further investigation. These findings revealed an infiltrate in the Ascites fluid and tissue. consistent with an acute myeoid leukemia. An initial complete blood count (CBC) was also performed with the results as shown, (reference ranges in parenthesis): a hemoglobin of 10.7 g/dl (14.0-18.0 g/dl), red blood cells (RBC) of 3.79 Mill/IL (4.50-5.90 Mill/IL), hematocrit of 34.0% (41.0-53.0%), MCV of 89.8 fl (80.0-100.0 fl), platelets of 92 per 1000/IL(150-400 1000/IL), and white blood cells of 3.2 1000/IL (4.3-10.0 1000/ìl). The patient was transferred to our institution for further clinical investigation.

Clinical Examination: At our institution, a complete blood count (CBC) was performed with the results as shown below and an accompanying peripheral blood specimen was sent for immunophenotyping.

Laboratory results:

Parameter	Value	Normal Value [Unit]
RBC	3.0	4.3-6.1 /pl
Hemoglobin	9.0	13.-17. g/dl
Hematocrit	0.26	0.38-0.52 l/l
MCV	87	83-97 fl
Plt	75	150-440 /nl
WBC	2.97	4.0-10.0 /nl
Neutrophils	1.43	1.8-7.7 /nl
Lymphocytes	0.83	1.0-4.8 /nl
Monocytes	0.68	0.2-0.8 /nl
Eosinophils		0-0.5 /nl
Differential	Results	at time of IM
Band Neutrophils		3-10 %
Segmented Neutrophils	48	50-70%
Lymphocytes	28	25-40 %
Atypical Lymphs		0 %
Monocytes	23	2-9 %
Eosinophils		2-4 %
Basophils	1	0-1 %
Metamyelocytes		0 %
Myelocytes		0 %
Promyelocytes		0 %
Blasts		0%
normoblasts		/ 100 L

Cytogenetics: Cytogenetics analysis was performed on the gastroscopy sample. Chromosomal analysis resulted in a clone with a number of aberrations in 8 analyzed metaphases which indicate a structurally altered male karyotype with an additional chromosome 8, with an unknown amount and origin of chromosomal material located on the terminal end of 8q24. An inversion 16 was also shown to be present in the blast cells. The trisomy 8 is observed in 5% of all acute myeloid leukemias and is associated with an intermediate risk.

Molecular genetics (incl. Southern blot, PCR): Molecular diagnostics testing indicated no evidence of cells with the t(8;21) and/or the AML 1 ETO fusion. There is proof of cells with an inversion of chromosome 16. and trisomy 8.

Other molecular diagnostics: Despite the presence of trisomy 8, this patient is not considered high risk since the inversion 16 remains an aberration with low risk stratification.

Diagnosis: Acute myeloid leukemia of the M4 Eo subtype

Differential diagnosis: Acute promyelocytic leukemia, acute myeloid leukemia that has progressed from a chronic myelomonocytic leukemia.