title: A case of clinical indolent natural killer cell lineage large granular lymphocytic leukemia in a patient with rheumatoid arthritis.
abstract: We report a case of natural killer (NK) cell leukemia with unusual biological features in a 65-year-old woman with a 20-year history of rheumatoid arthritis. She presented with neutropenia, thrombocytopenia, splenomegaly and bone marrow infiltration. Immunophenotyping (CD2+ CD3- CD4- CD5- CD8- CD16+ CD56-) confirmed NK cell leukemia. Her neutropenia and thrombocytopenia resolved following splenectomy and she has remained well with stable disease for 12 months on oral low-dose methotrexate. In contrast to all previous reports, in this instance the phenotype of large granular lymphocytic (LGL) leukemia occurring in the context of rheumatoid arthritis was NK-cell rather than T-cell. Furthermore, the clinical course was indolent, whereas, all prior literature reports have described a very aggressive clinical course for this disorder with a median survival of just 3.5 months. This case illustrates previously unrecognized heterogeneity in the natural history of this disorder.
authors.affiliation: Department of Haematology, Peter MacCallum Cancer Institute, St. Andrew's Place, East Melbourne, VIC 3002, Australia.
authors.forename: J N
authors.initials: JN
authors.lastname: Machatschek
authors.forename: D
authors.initials: D
authors.lastname: Westerman
authors.forename: H M
authors.initials: HM
authors.lastname: Prince
authors.forename: J F
authors.initials: JF
authors.lastname: Seymour
mesh_terms: D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000276:immunology / Q000473:pathology; D019070:Cell Lineage; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000473:pathology*; D007945:Leukemia, Lymphoid / Q000150:complications* / Q000276:immunology / Q000473:pathology
chemical_list: D015703:Antigens, CD