title: Two cases of concurrent development of essential thrombocythemia with chronic lymphocytic leukemia, one related to clonal B-cell lymphocytosis, tested by array comparative genomic hybridization.
abstract: We present two cases of concurrent development of essential thrombocythemia (ET) with chronic lymphocytic leukemia (CLL) and one related to clonal B-cell lymphocytosis (CBL). Both patients were referred for lymphocytosis and thrombocytosis. A bone marrow biopsy revealed infiltration of small, mature lymphocytes and megakaryocytic hyperplasia. Flow cytometric immunophenotyping and immunoglobulin (IG) gene clonality tests revealed clonal B lymphocytes. Both patients were positive for the JAK2 V617F mutation in whole bone marrow aspirate. The JAK2 V617F mutation was present in isolated B lymphocytes of patient 1, but not patient 2. Cytogenetics were normal in both patients. An array comparative genomic hybridization (CGH) analyses of B cells revealed a gain of 4q28.3, which is reported in non-Hodgkin's lymphoma, in patient 1, and deletion 22q11.22, which is associated with CLL, and a gain of Xp22.31 in patient 2. In both patients, B cells showed no myeloproliferative neoplasm (MPN)-specific genetic abnormalities. These results suggest that different oncogenic mechanisms in each cell lineage may underlie the concurrent development of ET and CLL (or CBL). Array CGH may be helpful in identifying the pathogenic mechanism in cases of concurrent development of lymphoid neoplasm and MPN.
authors.affiliation: Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Daejeon St. Mary's Hospital, Daejeon, 301-723, Korea (South).
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Kim
authors.forename: Woori
authors.initials: W
authors.lastname: Jang
authors.forename: Soyoung
authors.initials: S
authors.lastname: Shin
authors.forename: Joonhong
authors.initials: J
authors.lastname: Park
authors.forename: Myungshin
authors.initials: M
authors.lastname: Kim
authors.forename: Yonggoo
authors.initials: Y
authors.lastname: Kim
authors.forename: Kyungja
authors.initials: K
authors.lastname: Han
authors.forename: Gun Dong
authors.initials: GD
authors.lastname: Lee
authors.forename: Heusung
authors.initials: H
authors.lastname: Won
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Yang
mesh_terms: D000368:Aged; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D001792:Blood Platelets / Q000378:metabolism / Q000473:pathology; D001853:Bone Marrow / Q000473:pathology; D055028:Comparative Genomic Hybridization; D005260:Female; D015322:Gene Rearrangement, B-Lymphocyte; D006801:Humans; D050440:Immunoglobulin Subunits / Q000235:genetics; D053614:Janus Kinase 2 / Q000235:genetics; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000150:complications* / Q000235:genetics / Q000473:pathology; D008218:Lymphocytosis / Q000150:complications* / Q000235:genetics / Q000473:pathology; D008297:Male; D017354:Point Mutation; D013920:Thrombocythemia, Essential / Q000150:complications* / Q000235:genetics / Q000473:pathology
chemical_list: D050440:Immunoglobulin Subunits; C507924:JAK2 protein, human; D053614:Janus Kinase 2