Jumping translocations of chromosome 1q occurring by a multi-stage process in an acute myeloid leukemia progressed from myelodysplastic syndrome with a TET2 mutation

摘要

Peripheral blood shows marked leukocytosis with numerous blasts and promyelocytes, dyspoietic granulocytes with nuclear hypolobation and hypogranularity, and dyspoietic erythroid precursors. Bone marrow core biopsy is hypercellular for age (80%). Maturing granulopoiesis and erythropoiesis are replaced by sheets of immature cells. Megakaryocytes are decreased and have atypical morphology. Bone marrow aspirate consists of blasts which are intermediate in size with fine chromatin, prominent nucleoli and scant basophilic cytoplasm. A few dyspoietic maturing granulocytes and atypical megakaryocytes are present. Partial karyograms of a 46,XY,+ 1,der(1;21)(p10 or q10;q10) karyotype, a 46,XY,+ 1,del(1)(p12) karyotype, and 46,XY,+ 1,der(1;14)(p10 or q10;q10),i(18)(q10) karyotype. Whole-genome SNP microarray shows mosaic gain of chromosome 1 from 1p11 to 1qter regions and mosaic gain of chromosome 18q. Fusion sites of recipient chromosomes of 149 jumping translocations of 1q in 48 myeloid neoplasm patients (including our patient). A possible multi-stage process for the development and formation of 1q JTs in our patient.