Case 161

Submitting Author: Orduz, Y. Rocio, MD
Institution: Clinica Colsanitas, S.A.
Additional authors:Edwin Medina, Maria Teresa Urrego, Monica Zapata, Jorge Caro
Session: AML with recurrent genetic abnormalities Part I

HISTORY

In 2011 a 8 year-old girl who was taken by her parents for asthenia, adinamia and fatigue to one of our clinics in Bogota.

An extensive workup (CBC included) was performed. The CBC showed anemia, thrombocytopenia and leukocytosis without monocytosis.

In the PB smear, dysplastic changes were obvious with hypogranulation and hypersegmentation in neutrophils.

All causes of dysplasia as toxicity, nutritional factors, infections, drugs, etc were excluded.

DETAILS

Bone marrow smear shows increase of granulopoiesis and decrease of erythropoiesis and megakaryocytes. Marked dysplasia of granulopoiesis was evident.

Bone marrow biopsy is normocellular for age (95%) and shows increase of granulopoiesis and decrease of erythropoiesis and megakaryocytes.

BONE MARROW SMEAR AT DIAGNOSIS (Oct 19/2011):

Neutrophils:40%

Bands :4%

Metamyelocytes:6%

Myelocytes:12%

Promyelocytes:2%

Erytroid :8%

Lymphocytes :7%

Monocytes :5%

Eosinophils:8%

Plasma cells:5%

Blasts:3%

CBC AT DIAGNOSIS (Oct 18/2011):

Hb: 6.3 g/dl, Hct:19.5%, White cells: 25700, Plt:42000

Neutrophils:30%

Myelocytes:9%

Promyelocytes:1%

Lymphocytes:50%

Atypical lymphocytes:3%

Monocytes :5%

Immature cells:2%

CBC April 3/2013

Hb: 14.4 g/dl, Hct: 42.1%, White cells: 5080, Plt:280000

Neutrophils:64%

Lymphocytes :26%

Monocytes :8%

Eosinophils:2%

IMMUNOHISTOCHEMISTRY AND FLOW CYTOMETRY

CD34 and tdt in BM biopsy is less than 5% of the nucleated cells.

Immature cells by flow cytometry with TdT/CD34/CD117 were less than 2%.

A diagnosis of acute leukemia was excluded.

CYTOGENETIC FINDINGS

Cytogenetic studies showed t(8;21)(q22;q22) in 9 of 25 metaphases.

MOLECULAR FINDINGS

Qualitative PCR in PB for RUNX1-RUNX1T1 was positive (data not shown)

INTERESTING FEATURES

Myelodysplastic syndrome is very uncommon in children and difficult to address.

Despite the number of blast, cases with hematologic disease and t(8;21) should be classified as AML with t(8;21) as in this case. In fact, this girl was treated with the AML chemotherapy scheme after cytogenetic studies revealed t(8;21) and PCR for RUNX1-RUNX1T1 was positive. BM transplantation was considered but as AML with t(8;21) is associated with good prognosis, this treatment option was excluded. All parameters in her CBC of yesterday (January 28/2013) are normal.

PROPOSED DIAGNOSIS

ACUTE MYELOID LEUKEMIA WITH RECURRENT GENETIC ABNORMALITIES.

AML WITH t(8;21); RUNX1-RUNX1T1

CONSENSUS DIAGNOSIS

Oligoblastic acute myeloid leukemia with t(8;21)(q22;q22); RUNX1-RUNX1T1