The Philadelphia Chromosome as a Secondary Change in Leukemia: Three Case Reports and an Overview of the Literature

Secondary acute myelogenous leukemia and myelodysplasia without abnormalities of chromosome 11q23 following treatment of acute leukemia with topoisomerase II-based chemotherapy

“…However, the Philadelphia chromosome has also been reported to occur in cases of MDS and AML. 35,36 In the latter cases the Philadelphia chromosome can occur at diagnosis, or, rarely as a late event. 37 Pedersen-Bjergaard et al 12 reported the development of Philadelphia chromosome-positive secondary leukemias in 25 patients treated with topoisomerase II inhibitors for other malignancies.…”

Secondary Philadelphia chromosome and erythrophagocytosis in a relapsed acute myeloid leukemia after hematopoietic cell transplantation

“…Ph as a secondary change is usually late-appearing and may represent clonal evolution [5]. Clonal evolution is often apparent even before the occurrence of the Ph, and the original chromosomal abnormality commonly includes a monosomy 7, with or without additional abnormalities.…”

“…Alternatively, late-onset Ph may represent a therapy-related myeloid neoplasm in the absence of the initial chromosomal abnormality [6]. In late-developing Ph chromosome, both p190 bcr/abl mRNA and p210 bcr/abl mRNA have been reported, though it appears that the p190 variant of BCR/ABL-1 rearrangement may occur more frequently [5]. Secondary Ph occurring after HCT has been reported rarely in the literature [5, 6].…”

“…A secondary Philadelphia (Ph) chromosome appearing during the course of hematopoietic malignancies is rare and is associated with poor prognosis [1, 2] [3, 4]. Few cases of secondary Ph occurring after hematopoietic transplantation have been reported [5] [6]. We present a unique case of relapsed AML after allogeneic hematopoietic cell transplantation (HCT) that acquired a Ph along with erythrophagocytosis by blasts at the time of the relapse.…”

Late‐appearing MLL rearrangement arising as a secondary change in adult acute myeloid leukemia

“…The literature contains several reports of chromosome abnormalities or gene rearrangements that were initially considered solely as primary transforming changes, such as inv(3)(q21q26), t(15;17) (q22;q11-21), t(9;22)(q34;q11), and inv(16)(p13q22), but are now known to occur occasionally as secondary changes associated with disease progression (Chen et al, 1998). Some evidence exists that this may also be the case for MLL rearrangement.…”