Win K.T.Hsieh Y.-C.Yang C.-C.Chang S.-T.Su Y.-Z.HWEI-FANG TIENChuang S.-S.2021-01-042021-01-0420130884-6812https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885945849&partnerID=40&md5=2ee868d2f91df96b147e705de25878f0https://scholars.lib.ntu.edu.tw/handle/123456789/537446BACKGROUND: Large granular lymphocytes (LGLs) are either cytotoxic T or natural killer (NK) cells exhibiting round nuclei and azurophilic cytoplasmic granules.Morphologically, neoplastic LGLs of T cell lineage (TLGLLs) are usually indistinguishable from normal LGLs, while there is a wide morphological range of aggressive NK cell leukemia (ANKL). CASES: We present 2 consecutive cases of leukemia comprising pleomorphic LGLs. One patient presented with drowsy consciousness and unstablehemodynamics. Her peripheral blood smear disclosed a significant number of LGLs with pleomorphic nuclei expressing CD2, CD56 and HLA-DR but not surface or cytoplasmic CD3 (cCD3). The second patient, previously healthy, presented with a sudden death. Her peripheral blood revealed LGLs ranging from round to pleomorphic nuclei with a CD2+ cCD3+ surface CD3-CD56+ phenotype and clonally rearranged T cell receptor gene. The findings of the first patient were consistent with ANKL and the second, T-LGLL. Both patients passed away shortly before treatment. CONCLUSION: The 2 cases highlight the importance of a multidisciplinary approach in addition to cytological examination to reach accurate diagnoses of such rare leukemia cases. (Anal Quant Cytopathol Histopathol 2013;35:232-236). ? Science Printers and Publishers, Inc.Aggressive natural killer cell leukemia[SDGs]SDG3creatinine; hemoglobin; nitrogen; urea; CD2 antigen; CD56 antigen; HLA DR antigen; acute kidney failure; aged; aggressive NK cell leukemia; anemia; article; assisted ventilation; blood smear; case report; chromosome analysis; clonal variation; computer assisted tomography; consciousness; creatinine blood level; drowsiness; endotracheal intubation; Epstein Barr virus; female; flow cytometry; gene rearrangement; Glasgow coma scale; hemodynamics; human; hypertension; hypertransaminasemia; immunophenotyping; large granular lymphocyte; leukocyte count; liver function; lymphocyte count; lymphocytosis; natural killer cell; neutrophil count; non insulin dependent diabetes mellitus; phenotype; priority journal; resuscitation; sudden death; T lymphocyte receptor gene; thrombocyte count; thrombocytopenia; urea nitrogen blood level; antigen expression; Article; consciousness level; fatality; geriatric patient; laboratory test; large granular lymphocyte leukemia; liver disease; sepsis; very elderly; Aged; Aged, 80 and over; Biological Markers; Cell Lineage; Fatal Outcome; Female; Humans; Immunophenotyping; Killer Cells, Natural; Leukemia, Large Granular Lymphocytic; T-Lymphocytes, Cytotoxicjournal article243411272-s2.0-84885945849