Diagnostic value of flow cytometry in aggressive natural killer-cell leukemia: a case report and review of literatures / 白血病·淋巴瘤

Objective To explore clinical characteristics and diagnosis of aggressive natural killercell leukemia (ANKL),and evaluate the value of flow cytometry (FCM) in diagnosing it.Methods A case of ANKL was reported and literatures were reviewed.Results The patient presented with persistent high fever,progressive pancytopenia and hepatosplenomegaly.The untypical cells could be seen by morphology.By FCM,NK cells consisted 83.3 ％ of total lymphocytes in bone marrow and immunophenotypes were CD34-,CD2+,CD7+,CD3-,CyCD3+,CD5-,CD16+,CD56+,CD30-,CD4-,CD8-,CD117-,CD11c,CD19-,CD45++,SSC+-++.T-cell receptor (TCR) and IgH gene rearrangement were negative and chromosome was normal.The patient was diagonised ANKL eventually.Conclusions ANKL is a quite rare disease with highly aggressive,poor prognosis and could be misdiagnosed easily.FCM combined with morphology is a convenient,handy,practicable and less invasive device for the diagnosis,and can be a preferred detection technique in some cases.

A Case of Natural Killer Cell Leukemia Misdiagnosed as Tuberculous Lymphadenopathy / 대한진단검사의학회지

Natural killer (NK) cell neoplasms are a group of rare but highly malignant tumors. We report here one case of NK cell leukemia. A 54-yr-old woman presented with a 2-month history of progressive left neck mass. Based on the positive result of tissue PCR for Mycobacterium tuberculosis, she was at first diagnosed with tuberculous lymphadenopathy. After two weeks, she developed generalized lymphadenopathy, hepatosplenomegaly, fever and anemia. Subsequent evaluation was performed including bone marrow aspiration and biopsy. Peripheral blood smear showed leukoerythroblastic features with 31% blasts. Bone marrow was packed with agranular blastoid cells, which were periodic acid-Schiff (PAS) positive and myeloperoxidase (MPO) negative. Immunophenotyping showed that these cells were positive for CD45 and HLA-DR, whereas negative for CD3, CD5, CD7, CD10, CD13, CD14, CD19, CD20, CD22, CD33, CD34, and CD61. Because of the absence of the markers of T-cell, B-cell, and myeloid lineage-specific antigens, we added CD16/56 for the immunophenotyping and the blasts were positive (94%). The tumor cells of biopsied lymph node were only positive for CD56, consistent with NK cell lymphoma. Epstein-Barr virus (EBV) was not detected by RNA in situ hybridization. Culture for M. tuberculosis was negative. Thus this patient was diagnosed with blastic NK cell lymphoma/leukemia involving bone marrow and lymph node.

Frequent CD7 Antigen Loss in Aggressive Natural Killer-Cell Leukemia: A Useful Diagnostic Marker / 대한진단검사의학회지

BACKGROUND: Aggressive natural killer-cell leukemia (ANKL) is a rare neoplasm characterized by systemic proliferation of NK cells. However, the differential diagnosis of NK lymphoproliferative disorders is difficult because of the absence of a distinct diagnostic hallmark. Therefore, to identify diagnostic markers for ANKL, we analyzed the clinical data and laboratory findings obtained for 20 patients with ANKL. METHODS: From January 2000 to July 2007, 20 patients were diagnosed with ANKL on the basis of bone marrow studies. We retrospectively analyzed the clinical features and laboratory findings, including the complete blood count, Epstein-Barr virus status, immunophenotype, and the cytogenetic results. RESULTS: The subjects included 6 women and 14 men (median age, 44 yr; range, 2-70 yr). Cytogenetic studies were performed in 18 patients, and karyotypic abnormalities were observed in 9 patients (50%). None of the cytogenetic abnormalities were constantly observed in all the patients. However, 6q abnormalities were observed in 4 patients (4/18, 22%). The immunophenotype of the leukemic NK-cells was cytoplasmic CD3+, surface CD3-, CD16/56+, CD2+, and CD5-. Notably, the CD7 antigen was absent in 10 patients (50%). When the CD7 loss was combined with cytogenetic abnormalities, clonal markers could be identified in 75% of the ANKL cases. CONCLUSIONS: The CD7 antigen loss was frequently observed in our series of ANKL patients. In conjunction with the cytogenetic findings, this characteristic immunophenotypic finding can serve as a reliable marker for the timely diagnosis of ANKL. Therefore, immunophenotypic analysis of CD7 expression should be included in the diagnosis of NK cell neoplasms.

Quantifing the Circulating Epstein-Barr Virus (EBV) DNA to Monitor a Case of Aggressive Natural Killer Cell Leukemia

Epstein-Barr virus (EBV) infection is associated with various lymphoproliferative diseases, including Hodgkin lymphoma, extranodal NK/T cell lymphoma, aggressive NK cell leukemia, Burkitt lymphoma and post-transplant lymphoproliferative disorder. In the recent studies, the plasma EBV-DNA levels in patients with EBV-associated lymphoproliferative disease appeared to be correlated with the therapeutic response. Aggressive NK cell leukemia (ANKL) is a fatal disease that's characterized by high fever, lymphadenopathy, hepatosplenomegaly and frequent hemophagocytosis. No serological tumor marker for this malignancy has yet been identified for monitoring the disease and predicting the outcome. We experienced a case of aggressive natural killer cell leukemia in a 48-year-old man, and we serially monitored the plasma EBV DNA load by performing real time quantitative PCR assay. Serial measurements of the plasma EBV DNA level during therapy showed a close correlation between the clinical response and the changes in the plasma EBV DNA titers.

Natural killer cell neoplasms / 中国实用内科杂志

Lymphoid neoplasms that are derived from natural killer(NK) cells are uncommon but distinct clinicopathologic disease entities.In recent years,the conceptual view of NK cell neoplasms has changed as the result of further understanding of the cell derivations and the characteristics of the malignant counterparts.In this article,we reviewed the recent concepts and progress in clinicopathologic features,pathogenesis,diagnosis,treatment strategies,and outcomes of this group of uncommon neoplasms.