Possible cytogenetic distinction between lymphoid and myeloid blast crisis in chronic granulocytic leukemia

Abstract

This study consists of 25 patients with chronic granulocytic leukemia in blast crisis (BC) or with acute leukemia who had a Ph1 chromosome and one or more other chromosome abnormalities and who were investigated by cytochemistry and immunocytochemistry techniques to determine whether the predominant blasts were myeloid or lymphoid. The disorder was myeloid in 15 patients, lymphoid in 8, and mixed in 2. Among the 15 patients with myeloid disorders, 13 (86.6%) had an additional Ph1 chromosome, i(17q), +8, +19, or some combination of these abnormalities. None of the eight patients with a lymphoid disorder had +8, +19, or i(17q), but one had an additional Ph1 chromosome. Among the eight patients with lymphoid disorders, two had structural abnormalities of chromosome 7 and two were monosomy 7. None of the patients with myeloid disease had a structurally abnormal chromosome 7, but one was monosomy 7. Our findings suggest that the number of chromosomes in an abnormal clone may be unreliable for distinguishing between lymphoid and myeloid BC. Most patients with myeloid disease had only abnormal metaphases, whereas many patients with lymphoid disorders had both normal and abnormal metaphases. This finding may partially explain why many patients with lymphoid BC respond better to treatment than do those with myeloid BC.

Morphological and Immunological Pattern of Blastic Transformation in Chronic Myeloid Leukemia in Saudi Arabia: Study of 90 Transformations Among 248 Patients

“…The lymphoid-type transformation represented 32.2% (N = 29) of the total, a figure similar to those reported [4,5,13]. Of the patients tested, all were Ia and CD10 positive, with varying positivity for CD20 and CD19.…”

“…The reason why the chronic phase of CML transforms to a particular lineage of acute lymphocytic leukemia (ALL) is not known, but such transformations usually follow lines that are the normal developmental lines of the hematopoietic stem cell. Recent attempts have been made to correlate the additional cytogenetic changes that accompany or precede blast crisis with the lineage of the blast cells, but definitive patterns have not emerged [4,5].…”

Deletions and losses in chromosomes 5 or 7 in adult acute lymphocytic leukemia: incidence, associations and implications

“…Deletion of 7q was also reported in association with chronic lymphoid malignancy. 13 Little is known about the significance of chromosome 5 or 7 abnormalities in ALL 14,15 where chromosomal abnormalities have a major prognostic impact. 16 This study attempted to define the associations of chromosome 5 or 7 abnormalities in adult ALL, in relation to host and disease features, and to prognosis.…”

Applications of Fluorescence in Situ Hybridization (FISH) for Detecting Genetic Changes in Hematological Malignancies

“…A similar BCR/ABL1 fusion occurs in 17% of adults with ALL and 1% of patients with AML [14]. Some investigators have suggested that these Ph-positive forms of acute leukemia may be similar to lymphoid or myeloid blast crisis of CML [15]. Such findings emphasize the importance of performing baseline FISH studies and that these patterns are verified using metaphases since the signal patterns may change during the course of the disease.…”