Monoclonal Origin of Acute Transformation of Chronic Myelogenous Leukemia

Abstract

In a case of chronic myelogenous leukemia with an acquired sex chromosome mosaic (45, XO, PhV46, XY, Ph¹), variant cells, developed after blast crisis, were evidenced to have been originated from a 46, XY, Ph¹+ clone because of the constant presence of a Y chromosome in them. This strongly suggests that acute transformation has occurred selectively in a single clone.

Hyperdiploidy of 54 Chromosomes with Double Ph¹ Chromosome in Lymphoid Chronic Myelocytic Leukemic Blast Crisis

“…19) were affected in our patient, but iso chromosome 17q could not be detected. Often a mo saic of Ph'-positive and Ph'-negative cells can be found [19,20], new subclones originating from Ph'-negative clones [21]. In contrast to the report of Hagemeijer et al [21], our patient showed the evolu tion of a new cell clone without disappearance of the preexistent Ph1 chromosome.…”

Missing Y Chromosome in Ph1-Negative Chronic Myeloid Leukemia with bcr Rearrangement

“…Furthermore Motomura et al [20] have reported that in a patient with mosaic 46, XY, Phi +/45, X, -Y, Phi + clones, only 46, XY, Phl+ cells can be found after blast crisis, which may reveal the disadvantage of 45, X, -Y, Phl+ cells for blastic transformation. In this regard, a gradual de crease in 45, X, -Y, clone observed in the present case might possibly imply the occurrence of blast crisis in the near future, but the patient has not presented any clinical and hematological findings characteristic of the acute phase at all for more than 60 months.…”

Progression and Prognosis of Chronic Myelogenous Leukemia in the Acute Stage: Hematologic and Cytogenetic Aspects

“…CML is a clonal disease derived from a hemopoietic stem cell [1], and the acute blast transformation which develops in CML is also suggested to begin in a single stem cell with a Ph* chromosome [16]. It is well docu mented that the appearance of aneuploid clones which have not been ob served before in bone marrow cells of a patient with CML, either foresha dows or accompanies the development of acute transformation [18].…”

“…Karyotypes of these pa tients in the chronic stage were all diploid with one Ph1 chromosome except in case 1 [16]. They were all treated mainly with busulfan.…”

“…The total survival time of these patients was 7-100 months with a mean value of 36.1 months. The diagnosis of acute transformation was made according to the criteria of Canellos et al [2], Chromosome preparations of marrow and lymph node cells were made by the direct method, and peripheral leukocytes were cultured without PHA for 24 h [16]. Karyotype analysis of cases, especially with marker chromosomes, was made by the Giemsa banding technique [19].…”