Trisomy 8 in an elderly patient with acute lymphoblastic leukemia as a sole abnormality

High Throughput FISH Analysis: A New, Sensitive Option For Evaluation of Hematological Malignancies

Objective: The aim of this study was to determine the efficiency of the high throughput FISH analysis (HTFA) method for detecting genetic alterations in hematological malignancies, which is a new bacterial artificial chromosome array-based approach.

Materials and Methods: We performed a HTFA study of bone marrow aspiration and peripheral blood samples of 77 cases (n=19 myelodysplastic syndrome, n=17 acute lymphoblastic leukemia, n=9 chronic myeloid leukemia, n=32 acute myeloid leukemia) with hematological malignancies during the periods of initial diagnosis, treatment, and/or follow-up.

Results: Both numerical and structural abnormalities were detected by HTFA. We observed aberrations in 88% of our acute lymphoblastic leukemia patients, 25% of acute myeloid leukemia patients, and 31% of myelodysplastic syndrome patients. In chronic myeloid leukemia cases, aberration was not detected by HTFA.

Conclusion: Our results showed that HTFA, combined with other methods, will gradually take a place in the routine diagnosis of hematologic malignancies.

Adult B-cell acute lymphoblastic leukemia with two unrelated abnormal cytogenetic clones

The presence of two different abnormal cell lines at diagnosis in hematologic malignancies is rare and raises the question of etiology and pathogenesis--two separate malignant lineages occurring together or a common stem cell malignancy? We present a 64-year-old woman who was evaluated for low platelet count and peripheral blasts. On the basis of the morphology, flow cytometry, and lack of myeloid-associated markers, a diagnosis of precursor B-cell acute lymphoblastic leukemia (B-ALL) was made. Cytogenetic analysis of the diagnostic bone marrow (BM) specimen revealed two unrelated abnormal clones--one had a dicentric (7;9)(p11;p11), resulting in the deletion of 7p and 9p, and the other had only trisomy 8. The dic(7;9) is a rare but recurrent abnormality in B-ALL, while trisomy 8 as a sole abnormality is most commonly associated with myeloid malignancies. After standard treatment for B-ALL, BM cytogenetic analysis showed disappearance of the dic(7;9) cell line but persistence of cells with trisomy 8. The presence of two unrelated clones suggestive of concomitant malignancies, possibly B-ALL with an underlying MDS, may have arisen by different mechanisms.