Lymphoid neoplasms that are derived from natural killer (NK) cells are uncommon but distinct clinicopathologic disease entities. Three types have been recognized and categorized in the latest World Health Organization classification: extranodal NK cell lymphoma, nasal-type; aggressive NK cell leukemia; and blastic NK cell lymphoma. All NK tumor cells express the NK cell marker CD56, but they la...

Thirty-two natural killer (NK) and cytotoxic T-cell lymphomas and 14 noncytotoxic nodal T-cell lymphoma controls were immunostained with the use of monoclonal antibodies reactive against NK-cell receptor (NKR) molecules (CD94, NKG2A, p58.2, p58.1, p140, p70, p50.3). All NK-cell lymphomas (4 nasal/oral and 1 intestinal) expressed at least 1 NKR, the CD94/NKG2A complex. Two were positive for 1 or...

A population of cells that expresses the NK cell receptor NKp46 and produces interleukin (IL)-22 have recently attracted considerable attention. The identity of these cells is still the subject of speculation, being variably defined as a novel NK cell subset or as a population containing conventional NK (cNK) cell precursors. In this issue, two studies shed light on this conundrum, demonstratin...

Since nasal NK/T-cell lymphoma and NK/T-cell lymphoma nasal type are rare diseases, colonic involvement has seldom been seen. We report a case of a patient with a primary NK/T-cell lymphoma nasal type of the colon. The patient had no history of malignant diseases and was diagnosed after exhaustive study in the context of fever of unknown origin. The first therapeutic approach followed the DA-EP...

Non-Hodgkins lymphoma of the Natural Killer (NK) cell type is rare. World Health Organisation recognises 3 NK-cell phenotypic entities; extranodal NK/T cell lymphoma, nasal type (ENK/TL); aggressive NK cell leukaemia (ANKL); and chronic lymphoproliferative disorders of NK cells (CLPD-NK) which is classified as a provisional entity. Though specific clinical, morphological and immunophenotypic cr...

Extranodal NK/T-cell lymphoma represents less than 1% of all lymphomas, but is more common in Asia and South America. We present a 67-year-old female with a 10-month history of four reddish-blue firm and painful nodules in the parietal region of the head, ranging in size from 1 to 5 cm. Two nodules were taken for biopsy, which showed atypical lymphoid cells with angiocentric growth pattern. The...

Background: Primary cutaneous T cell lymphoma is a diverse and rare group of diseases with clinical manifestations that, if not biopsied, are easily confused benign skin diseases. Objective: To determine some features primary lymphomas classify them according to the 2018 update World Health Organization European Organisation for Research Treatment Cancer classification. Methods: case series stu...

OBJECTIVES This study aims to identify the presenting symptoms, treatment and outcome of patients with nasal natural killer T (NK/T)-cell lymphoma and to find possible differences in survival based on Ann-Arbor stage and international prognostic index (IPI). PATIENTS AND METHODS Computed tomography and biopsy results of 23 patients (15 males, 8 females; mean age 41 years; range 22 to 72 years...

This review covers the diagnosis and management of natural killer and peripheral T-cell lymphomas (PTCL). Problems with PTCL include their rarity, representing usually 10-15% of non-Hodgkin's lymphomas in the Western Hemisphere, morphologic heterogeneity, and lack of immunophenotypic markers for clonality. Additionally, their clinical behavior is variable and may not correlate with morphology. ...