title: Aggressive natural killer cell leukemia: report of a Chinese series and review of the literature.
abstract: Aggressive natural killer cell leukemia (ANKL) is a rare Epstein-Barr virus (EBV)-associated fulminating disease that is widely disseminated at diagnosis. Because of its typically extranodal presentation, differing degrees of NK cell involvement, and varying bone marrow pathology, ANKL can be confused with a reactive process. These features, coupled with a rapidly fatal course, have hampered systematic study of the pathogenesis of ANKL. Nine cases of ANKL were diagnosed and characterized by a single laboratory over a 2-year period. Constant features at presentation included disseminated disease, high fever, bone marrow involvement, and a high lactate dehydrogenase index. All cases were positive for EBV early region protein and negative for latent membrane protein 1, and all had a germline T-cell receptor gene configuration. Peripheral blood counts were variable, with severe thrombocytopenia being the most frequently encountered abnormality (7 of 9 cases). Hematophagocytosis, dyserythropoiesis, and stromal degeneration were the most frequent findings in the bone marrow. Neoplastic cells in the bone marrow were consistently CD2+, CD56+, CD45+, CD34-, CD117-, CD4-, and surface CD3-. Most cases were HLA-DR+ (8/9) and CD8- (8/9). Complex clonal cytogenetic abnormalities were found in 8 of 9 cases. Because of its aggressive course, rapid and accurate diagnosis of ANKL is essential for a better understanding of the etiology, pathogenesis, and treatment of the disease.
authors.affiliation: Sino-US Joint Clinical and Molecular Laboratory, Departement of Pathology, Fudan University, Shanghai, China.
authors.forename: John
authors.initials: J
authors.lastname: Ryder
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Wang
authors.forename: Liming
authors.initials: L
authors.lastname: Bao
authors.forename: Sherilyn A
authors.initials: SA
authors.lastname: Gross
authors.forename: Fu
authors.initials: F
authors.lastname: Hua
authors.forename: Richard D
authors.initials: RD
authors.lastname: Irons
mesh_terms: D000328:Adult; D000368:Aged; D001772:Blood Cell Count; D001855:Bone Marrow Diseases / Q000473:pathology; D002681:China; D020732:Cytogenetic Analysis; D005260:Female; D004854:Herpesvirus 4, Human; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000821:virology*; D015458:Leukemia, T-Cell / Q000175:diagnosis* / Q000453:epidemiology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D013921:Thrombocytopenia