RESUMO
Duplication of the long arm of chromosome 1 (1q) is widely reported in human neoplasia, including the myelodysplastic syndromes (MDS). So far, it has not been described as a single aberration in the chronic myelomonocytic leukemia (CMML), a subtype of MDS. Rather, trisomy 1q was always a part of complex chromosome changes affecting the subtypes of MDS other than CMML. We report on a patient with CMML with an unbalanced translocation of the entire 1q onto the short arm of chromosome 14 as a sole cytogenetic abnormality. Fluorescence in situ hybridization (FISH) analysis with an alpha-satellite probe for the paracentric region of the long arm of chromosome 1 confirmed the presence of trisomy 1q in a derivative chromosome, der(14)t(1;14)(q12;p11). The discrepant results between the metaphase cytogenetics (100% abnormal) and interphase cytogenetic (71% nuclei with 3 signals) suggest that trisomy 1q, even in the absence of additional cytogenetic changes, has a sufficient leukemogenic potential to confer a proliferative advantage on hematopoietic cells committed to monocyte stemline both in vitro and in vivo. The literature data on partial and complete trisomy 1q in CMML is reviewed.
Assuntos
Cromossomos Humanos Par 14 , Cromossomos Humanos Par 1 , Leucemia Mielomonocítica Crônica/genética , Translocação Genética , Adulto , Humanos , Masculino , TrissomiaRESUMO
A transformation of essential thrombocythemia to acute myelocytic leukemia (AML), myelodysplastic syndrome, or agnogenic myelocytic metaplasia is a relatively rare event. It occurs in 1%-4.5% of all patients with either treated or untreated essential thrombocythemia. Cytogenetic changes in the transformation to AML are common. We report the case of a patient treated for essential thrombocythemia with hydroxyurea for 49 months. He developed AML with a t(2;17), which to our knowledge has not been described in the literature.