Transferrin and structural anomalies of chromosome 3 in the blastic phase of chronic myelocytic leukemia

[A case of t(3;3)(q21;q26.2) associated with severe multilineage dysplasia and multi-drug resistance in blastic crisis of chronic myelogenous leukemia]

The t(3;3)(q21;q26.2) is known to be mainly observed in hematologic myeloid malignancies, as a form of 3q21q26 syndrome. Cytogenetic abnormalities of 3q21q26 syndrome result in RPN1-EVI1 fusion transcripts involving ecotropic viral integration site-1 (EVI1) at 3q26.2 and ribophorin I (RPN1) at 3q21, and the fusion transcripts play an important role in leukemogenesis and disease progression. They are usually associated with dysplasia, especially of megakaryocytes. Patients with these cytogenetic abnormalities show extremely poor prognosis even with aggressive anti-leukemic therapy. We report a case of blastic crisis of CML with both t(3;3)(q21;q26.2) and t(9;22)(q34;q11.2) and associated severe multilineage dysplasia. The patient showed a poor response to imatinib, dasatinib and aggressive induction therapy. When both t(3;3)(q21;q26.2) and t(9;22)(q34;q11.2) are observed in cases of leukemia with increased blasts, they are best considered as aggressive phases of CML with t(3;3)(q21;q26.2), rather than AML with t(9;22)(q34;q11.2) by 2008 WHO classification.

New case of t(3;17)(q26;q22) as an additional change in a Philadelphia-positive chronic myelogenous leukemia in acceleration

A new case of t(3;17)(q26;q22) was observed in a Philadelphia-positive (Ph+) chronic myelogenous leukemia in acceleration 1 month before occurrence of the blastic phase. Abnormal megakaryocytopoiesis and thrombopenia were noted, but blast cells did not express platelet markers. The same translocation was previously reported in three myeloproliferative disorders in acceleration or in the process of becoming acute. Translocations or inversions of chromosome 3 with breakpoint involving the band 3q26 were specifically associated with megakaryoblastic acute phase or abnormal megakaryocytopoiesis. This report confirms that the t(3;17)(q26;q22) is a specific nonrandom chromosomal abnormality associated with the acute nonlymphoblastic phase of myeloproliferative disorders and megakaryocytopoiesis dysfunction.

Three new cases of chromosome 3 rearrangement in bands q21 and q26 with abnormal thrombopoiesis bring further evidence to the existence of a 3q21q26 syndrome

Defects of 3q in bands q21 and q26 have been reported in more than 70 cases of acute nonlymphocytic leukemia (ANLL), myelodysplastic syndrome (MDS), and myeloproliferative disorder (MPD) in blast crisis. In this paper three additional patients are described: patient 1 with refractory anemia with excess of blasts in transformation (RAEB-T) and inv(3)(q21q26), patient 2 with RAEB-T and t(3;3)(q21;q26), and patient 3 with myelofibrosis with myeloid metaplasia (MMM) in blast crisis and inv(3)(q21q26). In addition to 3q rearrangements, monosomy 7 and del(7)(q22q36) were observed in patients 1 and 2, respectively. In the three patients, the most characteristic clinical features were elevated platelet counts, marked hyperplasia with dysplasia of the megakaryocytes, and poor prognosis. Although disturbance of thrombopoiesis was not systematically observed in all patients with t(3;3)(q21;q26), inv(3)(q21q26), and ins or dup(3)(q21----q26), study of the 77 cases reported and of the three cases presented here brings further evidence to the existence of a cytogenetic syndrome involving bands q21 and q26 simultaneously, which represents a subtype of ANLL, MDS, and MPD, characterized by normal or elevated platelet counts, hyperplasia with dysplasia of megakaryocytes, multilineage involvement, young median age of patients with MDS, preferential involvement of women in t(3;3), high incidence of chromosome 7 defects in MDS and ANLL, short duration of the MDS phase, no response to chemotherapy, short survival, and por prognosis.