+ The patient had thrombocytopenia for 10 years (platelet counts ranged between 70x106/L to 130x106/L, for what he had never received any treatment.

-

-

-

47 yrs

M

-

-

-

-

2.5

8.6

6

43

The bone marrow was hypocellular with 6.5% blasts at presentation. 7 months later, the patient MDS transformed to AML and his bone marrow biopsy showed markedly hypercellular marrow with 69% blasts (0.4% promyelocytes, 2.7% myelocytes, 1.1% neutrophils, 1.8% lymphocytes and 25% erythroblasts).

Acute myeloid leukemia without maturation

Myeloid immunophenotype, (positive for CD13, CD33, CD34, HLDR, CS45 and CD117) with aberrant expression of CD7.

AML with myelodysplasia-related changes. Provisional entity: AML with BCR/ABL1

08-2011

After the patient was diagnosed with MDS, therapy with decitabine was administrated but the patient remained cytopenic. At progression chemotherapy combined with imatinib (400 mg/day) was administrated that was escalated to 800 mg/day two weeks later.

-

A

04-2012

7+ The patient had traveled to his native country for further treatment.

bone marrow

24

G-banding

47,XY,t(6;17)(p21;p13),+8 [10]/46,XY [10] at presentation; 47,XY,t(6;17)(p21;p13),+8,t(9;22)(q34;q11)[18]/48,XY,t(6;17)(p21;p13),+8,t(9;22)(q34;q11),+10 [2]/46,XY [20 ] at transition

Fluorescence in situ hybridization studies (FISH) were performed on slides prepared for cytogenetic analysis using a t(9;22) specific BCR/ABL dual color, dual fusion, CEP 8 and LSI P53 probes (Abott Molecular/Vysis, US).

Breakpoint on 17p13 prompted us to search for deletion of the p53 gene at presentation; however fluorescence in situ hybridization with LSI p53 probe revealed only the presence of 2 normal P53 signals in 500 interphase cells. Hybridization with chromosome 8 centromeric probe showed extra chromosome +8 in 50 % of cells. FISH studies with BCR/ABL performed at transition revealed 60% positive cells while retrospective studies performed on stored bone marrow cells from MDS phase failed to detect either the Philadelphia chromosome, either the BCR/ABL1 rearrangement.

Molecular studies were performed from total RNA extracted from the bone marrow sample using the TriZol LS reagent (Invitrogen, US) according to the manufacturer s recommendations. cDNA was prepared from 2μg of total RNA with the Superscript II cDNA Synthesis Kit (Invitrogen, US) according to manufacturer s instructions.

Quantitative molecular studies performed with GeneXpert (Cepheid, US) were negative for the major BCR/ABL1 transcript. The absence of p210 BCR-ABL1 transcript was confirmed by reverse transcription-polymerase chain reaction analysis; however it showed breakpoint cluster region rearrangement between exons e1 and a2, compatible with the minor p190 BCR/ABL1 transcript.

We described a rare t(6;17)(p21;p13) (La Starza et al., 26) in a patient diagnosed with myelodysplastic syndrome that terminated in AML associated with acquisition of the Philadelphia chromosome translocation and the p190 BCR-ABL1 transcript. The patient initially had thrombocytopenia for 10 years, but developed MDS and at that time karyotyping revealed the chromosomal translocation t(6;17)(p21;p13) associated with an extra chromosome 8. The initial myelodysplastic syndrome terminated to acute myeloid leukemia, accompanied by an appearance of a new clone, characterized by a Philadelphia chromosome. Reverse transcription-polymerase chain reaction analysis further revealed the presence of the minor p190 BCR-ABL1 transcript. Developing a Philadelphia chromosome, considered a primary anomaly, during the course of MDS is extremely rare phenomenon, described only in few patients (Melo et al., 1994; Onozawa et al., 2003; Advani et al., 2004; Keung et al., 2004). Our study illustrates that the Ph translocation may develop from an existing MDS clone, accompanying or perhaps inducing disease transformation. The availability of preleukemic MDS phase in our patient offers an unique opportunity to analyze the role of BCR-ABL1 in leukemogenesis and the evolution of leukemia clones in hematological malignancies.