title: Isodicentric 20q- in two cases of B-cell acute lymphocytic leukemia with the respective t(9;20)(p11;q11.2) and t(9;22)(q34;q11.2).
abstract: The cytogenetic anomaly der(20)del(20)(q11.2q13.3)idic(20)(p11), or idic(20q-) in short form, has been reported in 13 cases of myelodysplastic syndrome, one case of chronic myelomonocytic leukemia, and one case of acute myeloid leukemia since 2004. To our knowledge, it has not previously been described in lymphoid diseases. Here we report the cases of two patients with B-cell acute lymphocytic leukemia (ALL) having a novel idic(20q-). One was a 34-year-old man with B-cell ALL whose leukemic cells at presentation had a karyotype of 45,XY,dic(9;20)(p11;q11.2); at relapse, a small marker chromosome was found coexisting with the dic(9;20). The other was a 39-year-old woman with Ph-positive B-cell-ALL whose leukemic cells contained both t(9;22)(q34;q11.2) and a small marker chromosome. A series of FISH analyses using the appropriate probes revealed the small marker chromosome in both patients to be an idic(20q-), confirming the dic(9;20)(p11;q11.2) in one case and revealing a BCR/ABL fusion gene in the other. One patient achieved complete remission but relapsed; the other did not achieve complete remission. Both patients died with a short survival time, despite receiving intensive chemotherapy. These two cases show that idic(20q-) can appear not only in myeloid diseases but also in lymphoid diseases.
authors.affiliation: The First Affiliated Hospital of Soochow University, Jiangsu Institute of Haematology, 188 Shizi Street, Suzhou, 215006, People's Republic of China.
authors.forename: Tianyu
authors.initials: T
authors.lastname: Li
authors.forename: Yongquan
authors.initials: Y
authors.lastname: Xue
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Suning
authors.initials: S
authors.lastname: Chen
authors.forename: Jinlan
authors.initials: J
authors.lastname: Pan
authors.forename: Yafang
authors.initials: Y
authors.lastname: Wu
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Shen
mesh_terms: D000328:Adult; D002871:Chromosome Banding; D002874:Chromosome Mapping; D002890:Chromosomes, Human, Pair 20; D002892:Chromosomes, Human, Pair 22; D002899:Chromosomes, Human, Pair 9; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D015448:Leukemia, B-Cell / Q000235:genetics*; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D014178:Translocation, Genetic