Acute promyelocytic transformation of chronic myeloid leukaemia with an isochromosome 17q

Promyelocytic crisis of chronic myelogenous leukaemia during imatinib mesylate treatment

An untreated 66-year-old woman with chronic myelogenous leukaemia (CML) in the chronic phase was initially given imatinib mesylate, rapidly achieving a good cytogenetic response with treatment. However, acute promyelocytic leukaemia complicated by a disseminated intravascular coagulation occurred 9 months after beginning imatinib treatment. Promyelocytic crisis of CML was diagnosed by demonstration of both BCR/ABL and PML/RAR alpha chimeric genes in leukaemic cells by karyotypic and fluorescence in situ hybridization analysis. Clonal evolution with addition of the PML/RAR alpha translocation may have arisen in the early chronic phase of CML, with expansion of this clone during imatinib treatment. Promyelocytic crisis of CML is rare; furthermore, we know of no previous report of promyelocytic crisis occurring during treatment with imatinib.

Patterns of clonal evolution in transformed chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) is an initially indolent disease which transforms into an acute leukemia about 2-5 years after diagnosis. We report a series of 75 patients, from a total of 125 patients with CML, who underwent acute blastic transformation. These included four unclassified, 10 lymphoid, and 61 non-lymphoid acute leukemias, including 54 myeloblastic, three promyelocytic, one myelomonocytic, one erythroblastic, and two megakaryoblastic leukemias. Fifty-two patients developed new cytogenetic abnormalities in addition to being Ph positive. These included trisomies of chromosomes 8, 19, and 21, isochromosome of the long arm of chromosome 17 (i(17q)), double and triple Ph, as well as other translocations, deletions, and additions. The overall median survival once the diagnosis of acute blast crisis was made was 61 days.

Multiple clones with (3;21) translocation in a case of Ph-positive chronic myelogenous leukemia during relapse after allogeneic bone marrow transplantation

Secondary chromosome changes are frequently observed during the blastic phase of chronic myelogenous leukemia (CML) owing to clonal evolution. Both numerical and structural abnormalities are reported in most of these cases. Recently a new translocation, t(3;21)(q26;q22), was reported in Philadelphia (Ph)-positive CML during the chronic as well as accelerated phase. We report a patient with Ph-positive CML who developed three abnormal clones, all of which had t(3;21) at the time of relapse after allogeneic bone marrow transplantation during the accelerated phase.

Promyelocytic blast crisis of Philadelphia-positive thrombocythemia with translocations (9;22) and (15;17)

We report a promyelocytic blast crisis in a case of Ph-positive thrombocythemia with both t(9;22) and t(15;17). Our patient confirms the specificity of t(15;17) in malignant proliferation of promyelocytes and suggests its appearance as a second genetic event in the genesis of blast crisis occurring in a Ph-positive clone.