Natural killer (NK) cell lymphomas are rare malignancies. They are classified as extranodal NK/T-cell lymphoma, nasal type, and aggressive NK cell leukemia. NK cell neoplasms are prevalent in Asian and South American populations, but are extremely rare in the West. They can be classified clinically into nasal, non-nasal, and aggressive lymphoma/leukemia subtypes. For nasal NK cell lymphomas, co...

Extranodal natural killer T-cell lymphoma, nasal type (ENKL), formerly called lethal midline granuloma or angiocentric T-cell lymphoma, is a predominantly extranodal non-Hodgkin lymphoma characterized by vascular damage, necrosis, and an association with Epstein-Barr virus. In the United States, it is more frequently seen in Asian, Asian Pacific Islander, and Hispanic descent populations and is...

Aggressive nature killer (NK)-cell neoplasm includes aggressive NK-cell leukemia (ANKL) and extranodal NK/T-cell lymphoma (ENKTL), nasal type. ANKL is rare and is characterized by a systemic neoplastic proliferation of NK-cells, usually with a leukemic presentation. ENKTL is a predominantly extranodal lymphoma, occurring mainly in the upper aerodigestive tract. Both are aggressive neoplasms str...

Natural killer (NK) cell malignancy is a heterogeneous disorder and rare, representing <1% of non-Hodgkin lymphomas for most of the world, except in Asia and Latin America. In Asia, especially, the incidence of NK-cell lymphomas is approximately 7%–10% of lymphomas [Au et al., 2005]. The pathogenesis of NK-cell malignancies has not yet been fully elucidated. In the 2008 World Health Organizatio...

Extranodal natural killer (NK)/T-cell lymphomas are rare tumors that account for 1.5% of all non-Hodgkin-type lymphomas in the United States and almost 7–10% of all non-Hodgkin’s lymphomas in Asia and South America. The nasal type commonly presents with facial cellulitis, nasal obstruction or proptosis. Occasionally, local extension from the nasal cavity causes destruction of the hard palate, p...

EBV-associated T/NK-cell lymphoproliferative disease (T/NK-LPD) is defined as a systemic illness characterized by clonal proliferation of EBV-infected T or NK cells. We prospectively enrolled 108 nonimmunocompromised patients with this disease (50 men and 58 women; median onset age, 8 years; age range, 1-50 years) evidenced by expansion of EBV(+) T/NK cells in the peripheral blood; these were o...

Introduction: Mature T and NK-cell lymphomas represent a heterogeneous group of lymphoid disorders (29 subtypes according to the 2016 WHO classification) arising from mature cells post-thymic origin with different morphological characteristics, phenotypes, clinical presentation. Following success Cell Project (TCP), which allowed analysis more than 1,500 cases peripheral T-Cell (PTCLs) collecte...