Changes

Extranodal NK/T-cell lymphoma (ENKTL) is a lymphoma of NK or T-cell lineage strongly associated with Epstein-Barr virus (citation needed)

Extranodal NK/T-cell lymphoma (ENKTL) is a lymphoma of NK or T-cell lineage strongly associated with Epstein-Barr virus (citation needed)

ENKTL is a destructive angiocentric disease characterized by vascular destruction and necrosis (citation needed)

ENKTL is a destructive angiocentric disease characterized by vascular destruction and necrosis (citation needed)

==Morphologic Features==

==Morphologic Features==

* Diffuse lymphomatous infiltrate composed of small, medium, or large and anaplastic cells (or a mix of small and large cells). The cells have irregularly folded nuclei and moderate pale cytoplasm.  

*Diffuse lymphomatous infiltrate composed of small, medium, or large and anaplastic cells (or a mix of small and large cells). The cells have irregularly folded nuclei and moderate pale cytoplasm.

* Loss of mucosal glands.

*Loss of mucosal glands.

* Angiocentric and angiodestructive growth pattern.

*Angiocentric and angiodestructive growth pattern.

* Coagulative necrosis and apoptosis.  

*Coagulative necrosis and apoptosis.

* Mitotic figures.

*Mitotic figures.

Pitfalls:

Pitfalls:

* Mucosal ulceration and superimposed inflammation can mimic an inflammatory process, particularly in less aggressive cases<ref>Devins, K., Schuster, S.J., Caponetti, G.C. ''et al.'' Rare case of low-grade extranodal NK/T-cell lymphoma, nasal type, arising in the setting of chronic rhinosinusitis and harboring a novel N-terminal ''KIT'' mutation. ''Diagn Pathol'' 13, 92 (2018). <nowiki>https://doi.org/10.1186/s13000-018-0765-1</nowiki></ref>.

*Mucosal ulceration and superimposed inflammation can mimic an inflammatory process, particularly in less aggressive cases<ref>Devins, K., Schuster, S.J., Caponetti, G.C. ''et al.'' Rare case of low-grade extranodal NK/T-cell lymphoma, nasal type, arising in the setting of chronic rhinosinusitis and harboring a novel N-terminal ''KIT'' mutation. ''Diagn Pathol'' 13, 92 (2018). <nowiki>https://doi.org/10.1186/s13000-018-0765-1</nowiki></ref>.

* Pseudoepitheliomatous hyperplasia of the overlying mucosal epithelium can mimic squamous cell carcinoma<ref>{{Cite journal|last=Ling|first=Yi-Hong|last2=Zhu|first2=Chong-Mei|last3=Wen|first3=Shi-Hong|last4=Luo|first4=Rong-Zhen|last5=Li|first5=Peng|last6=Cao|first6=Yun|last7=Rao|first7=Hui-Lan|last8=Lin|first8=Su-Xia|last9=Cai|first9=Mu-Yan|date=2015-09|title=Pseudoepitheliomatous hyperplasia mimicking invasive squamous cell carcinoma in extranodal natural killer/T-cell lymphoma: a report of 34 cases|url=https://pubmed.ncbi.nlm.nih.gov/25619876|journal=Histopathology|volume=67|issue=3|pages=404–409|doi=10.1111/his.12656|issn=1365-2559|pmid=25619876}}</ref><ref>{{Cite journal|last=Xiang|first=Chun-Xiang|last2=Chen|first2=Zi-Hang|last3=Zhao|first3=Sha|last4=Gao|first4=Li-Min|last5=Tao|first5=Qing|last6=Zuo|first6=Zhuo|last7=Liu|first7=Xiao-Yu|last8=Liu|first8=Wei-Ping|date=2019-07|title=Laryngeal Extranodal Nasal-type Natural Killer/T-cell Lymphoma: A Clinicopathologic Study of 31 Cases in China|url=https://pubmed.ncbi.nlm.nih.gov/31045893|journal=The American Journal of Surgical Pathology|volume=43|issue=7|pages=995–1004|doi=10.1097/PAS.0000000000001266|issn=1532-0979|pmid=31045893}}</ref>.

*Pseudoepitheliomatous hyperplasia of the overlying mucosal epithelium can mimic squamous cell carcinoma<ref>{{Cite journal|last=Ling|first=Yi-Hong|last2=Zhu|first2=Chong-Mei|last3=Wen|first3=Shi-Hong|last4=Luo|first4=Rong-Zhen|last5=Li|first5=Peng|last6=Cao|first6=Yun|last7=Rao|first7=Hui-Lan|last8=Lin|first8=Su-Xia|last9=Cai|first9=Mu-Yan|date=2015-09|title=Pseudoepitheliomatous hyperplasia mimicking invasive squamous cell carcinoma in extranodal natural killer/T-cell lymphoma: a report of 34 cases|url=https://pubmed.ncbi.nlm.nih.gov/25619876|journal=Histopathology|volume=67|issue=3|pages=404–409|doi=10.1111/his.12656|issn=1365-2559|pmid=25619876}}</ref><ref>{{Cite journal|last=Xiang|first=Chun-Xiang|last2=Chen|first2=Zi-Hang|last3=Zhao|first3=Sha|last4=Gao|first4=Li-Min|last5=Tao|first5=Qing|last6=Zuo|first6=Zhuo|last7=Liu|first7=Xiao-Yu|last8=Liu|first8=Wei-Ping|date=2019-07|title=Laryngeal Extranodal Nasal-type Natural Killer/T-cell Lymphoma: A Clinicopathologic Study of 31 Cases in China|url=https://pubmed.ncbi.nlm.nih.gov/31045893|journal=The American Journal of Surgical Pathology|volume=43|issue=7|pages=995–1004|doi=10.1097/PAS.0000000000001266|issn=1532-0979|pmid=31045893}}</ref>.

==Immunophenotype==

==Immunophenotype==

The majority of cases are positive for cytoplasmic CD3ε, CD2, granzyme B, and TIA-1. Most ENKTLs are of NK-lineage and express CD56. Cases of T-lineage express T-cell receptor (TCR) and show clonal TCR gene rearrangements. All cases are EBV positive by in situ hybridization for Epstein-Barr virus-encoded small RNA (EBER). Other markers that may be expressed include pSTAT3, CXCL13, IRF4/MUM1, CD16, Fas, FasL, MATK, and CD30<ref>{{Cite journal|last=Li|first=Shaoying|last2=Feng|first2=Xiaoli|last3=Li|first3=Ting|last4=Zhang|first4=Shuang|last5=Zuo|first5=Zhuang|last6=Lin|first6=Pei|last7=Konoplev|first7=Sergej|last8=Bueso-Ramos|first8=Carlos E.|last9=Vega|first9=Francisco|date=2013-01|title=Extranodal NK/T-cell lymphoma, nasal type: a report of 73 cases at MD Anderson Cancer Center|url=https://pubmed.ncbi.nlm.nih.gov/23232851|journal=The American Journal of Surgical Pathology|volume=37|issue=1|pages=14–23|doi=10.1097/PAS.0b013e31826731b5|issn=1532-0979|pmid=23232851}}</ref><ref>{{Cite journal|last=Jhuang|first=Jie-Yang|last2=Chang|first2=Sheng-Tsung|last3=Weng|first3=Shih-Feng|last4=Pan|first4=Shien-Tung|last5=Chu|first5=Pei-Yi|last6=Hsieh|first6=Pin-Pen|last7=Wei|first7=Chih-Hsin|last8=Chou|first8=Shih-Cheng|last9=Koo|first9=Chiew-Loon|date=2015-02|title=Extranodal natural killer/T-cell lymphoma, nasal type in Taiwan: a relatively higher frequency of T-cell lineage and poor survival for extranasal tumors|url=https://pubmed.ncbi.nlm.nih.gov/25554090|journal=Human Pathology|volume=46|issue=2|pages=313–321|doi=10.1016/j.humpath.2014.11.008|issn=1532-8392|pmid=25554090}}</ref><ref>{{Cite journal|last=Pongpruttipan|first=Tawatchai|last2=Sukpanichnant|first2=Sanya|last3=Assanasen|first3=Thamathorn|last4=Wannakrairot|first4=Pongsak|last5=Boonsakan|first5=Paisarn|last6=Kanoksil|first6=Wasana|last7=Kayasut|first7=Kanita|last8=Mitarnun|first8=Winyou|last9=Khuhapinant|first9=Archrob|date=2012-04|title=Extranodal NK/T-cell lymphoma, nasal type, includes cases of natural killer cell and αβ, γδ, and αβ/γδ T-cell origin: a comprehensive clinicopathologic and phenotypic study|url=https://pubmed.ncbi.nlm.nih.gov/22314189|journal=The American Journal of Surgical Pathology|volume=36|issue=4|pages=481–499|doi=10.1097/PAS.0b013e31824433d8|issn=1532-0979|pmid=22314189}}</ref><ref>{{Cite journal|last=Jaffe|first=E. S.|last2=Chan|first2=J. K.|last3=Su|first3=I. J.|last4=Frizzera|first4=G.|last5=Mori|first5=S.|last6=Feller|first6=A. C.|last7=Ho|first7=F. C.|date=1996-01|title=Report of the Workshop on Nasal and Related Extranodal Angiocentric T/Natural Killer Cell Lymphomas. Definitions, differential diagnosis, and epidemiology|url=https://pubmed.ncbi.nlm.nih.gov/8540601|journal=The American Journal of Surgical Pathology|volume=20|issue=1|pages=103–111|doi=10.1097/00000478-199601000-00012|issn=0147-5185|pmid=8540601}}</ref><ref>{{Cite journal|last=Ohshima|first=K.|last2=Suzumiya|first2=J.|last3=Shimazaki|first3=K.|last4=Kato|first4=A.|last5=Tanaka|first5=T.|last6=Kanda|first6=M.|last7=Kikuchi|first7=M.|date=1997-11|title=Nasal T/NK cell lymphomas commonly express perforin and Fas ligand: important mediators of tissue damage|url=https://pubmed.ncbi.nlm.nih.gov/9416485|journal=Histopathology|volume=31|issue=5|pages=444–450|doi=10.1046/j.1365-2559.1997.2880887.x|issn=0309-0167|pmid=9416485}}</ref><ref>{{Cite journal|last=Takata|first=Katsuyoshi|last2=Hong|first2=Min-Eui|last3=Sitthinamsuwan|first3=Panitta|last4=Loong|first4=Florence|last5=Tan|first5=Soo-Yong|last6=Liau|first6=Jau-Yu|last7=Hsieh|first7=Pin-Pen|last8=Ng|first8=Siok-Bian|last9=Yang|first9=Sheau-Fang|date=2015-01|title=Primary cutaneous NK/T-cell lymphoma, nasal type and CD56-positive peripheral T-cell lymphoma: a cellular lineage and clinicopathologic study of 60 patients from Asia|url=https://pubmed.ncbi.nlm.nih.gov/25188863|journal=The American Journal of Surgical Pathology|volume=39|issue=1|pages=1–12|doi=10.1097/PAS.0000000000000312|issn=1532-0979|pmid=25188863}}</ref>.

The majority of cases are positive for cytoplasmic CD3ε, CD2, granzyme B, and TIA-1. Most ENKTLs are of NK-lineage and express CD56. Cases of T-lineage express T-cell receptor (TCR) and show clonal TCR gene rearrangements. All cases are EBV positive by in situ hybridization for Epstein-Barr virus-encoded small RNA (EBER). Other markers that may be expressed include HLA-DR, CD25, pSTAT3, CXCL13, IRF4/MUM1, CD16, Fas, FasL, MATK, and CD30<ref>{{Cite journal|last=Li|first=Shaoying|last2=Feng|first2=Xiaoli|last3=Li|first3=Ting|last4=Zhang|first4=Shuang|last5=Zuo|first5=Zhuang|last6=Lin|first6=Pei|last7=Konoplev|first7=Sergej|last8=Bueso-Ramos|first8=Carlos E.|last9=Vega|first9=Francisco|date=2013-01|title=Extranodal NK/T-cell lymphoma, nasal type: a report of 73 cases at MD Anderson Cancer Center|url=https://pubmed.ncbi.nlm.nih.gov/23232851|journal=The American Journal of Surgical Pathology|volume=37|issue=1|pages=14–23|doi=10.1097/PAS.0b013e31826731b5|issn=1532-0979|pmid=23232851}}</ref><ref>{{Cite journal|last=Jhuang|first=Jie-Yang|last2=Chang|first2=Sheng-Tsung|last3=Weng|first3=Shih-Feng|last4=Pan|first4=Shien-Tung|last5=Chu|first5=Pei-Yi|last6=Hsieh|first6=Pin-Pen|last7=Wei|first7=Chih-Hsin|last8=Chou|first8=Shih-Cheng|last9=Koo|first9=Chiew-Loon|date=2015-02|title=Extranodal natural killer/T-cell lymphoma, nasal type in Taiwan: a relatively higher frequency of T-cell lineage and poor survival for extranasal tumors|url=https://pubmed.ncbi.nlm.nih.gov/25554090|journal=Human Pathology|volume=46|issue=2|pages=313–321|doi=10.1016/j.humpath.2014.11.008|issn=1532-8392|pmid=25554090}}</ref><ref>{{Cite journal|last=Pongpruttipan|first=Tawatchai|last2=Sukpanichnant|first2=Sanya|last3=Assanasen|first3=Thamathorn|last4=Wannakrairot|first4=Pongsak|last5=Boonsakan|first5=Paisarn|last6=Kanoksil|first6=Wasana|last7=Kayasut|first7=Kanita|last8=Mitarnun|first8=Winyou|last9=Khuhapinant|first9=Archrob|date=2012-04|title=Extranodal NK/T-cell lymphoma, nasal type, includes cases of natural killer cell and αβ, γδ, and αβ/γδ T-cell origin: a comprehensive clinicopathologic and phenotypic study|url=https://pubmed.ncbi.nlm.nih.gov/22314189|journal=The American Journal of Surgical Pathology|volume=36|issue=4|pages=481–499|doi=10.1097/PAS.0b013e31824433d8|issn=1532-0979|pmid=22314189}}</ref><ref>{{Cite journal|last=Jaffe|first=E. S.|last2=Chan|first2=J. K.|last3=Su|first3=I. J.|last4=Frizzera|first4=G.|last5=Mori|first5=S.|last6=Feller|first6=A. C.|last7=Ho|first7=F. C.|date=1996-01|title=Report of the Workshop on Nasal and Related Extranodal Angiocentric T/Natural Killer Cell Lymphomas. Definitions, differential diagnosis, and epidemiology|url=https://pubmed.ncbi.nlm.nih.gov/8540601|journal=The American Journal of Surgical Pathology|volume=20|issue=1|pages=103–111|doi=10.1097/00000478-199601000-00012|issn=0147-5185|pmid=8540601}}</ref><ref>{{Cite journal|last=Ohshima|first=K.|last2=Suzumiya|first2=J.|last3=Shimazaki|first3=K.|last4=Kato|first4=A.|last5=Tanaka|first5=T.|last6=Kanda|first6=M.|last7=Kikuchi|first7=M.|date=1997-11|title=Nasal T/NK cell lymphomas commonly express perforin and Fas ligand: important mediators of tissue damage|url=https://pubmed.ncbi.nlm.nih.gov/9416485|journal=Histopathology|volume=31|issue=5|pages=444–450|doi=10.1046/j.1365-2559.1997.2880887.x|issn=0309-0167|pmid=9416485}}</ref><ref>{{Cite journal|last=Takata|first=Katsuyoshi|last2=Hong|first2=Min-Eui|last3=Sitthinamsuwan|first3=Panitta|last4=Loong|first4=Florence|last5=Tan|first5=Soo-Yong|last6=Liau|first6=Jau-Yu|last7=Hsieh|first7=Pin-Pen|last8=Ng|first8=Siok-Bian|last9=Yang|first9=Sheau-Fang|date=2015-01|title=Primary cutaneous NK/T-cell lymphoma, nasal type and CD56-positive peripheral T-cell lymphoma: a cellular lineage and clinicopathologic study of 60 patients from Asia|url=https://pubmed.ncbi.nlm.nih.gov/25188863|journal=The American Journal of Surgical Pathology|volume=39|issue=1|pages=1–12|doi=10.1097/PAS.0000000000000312|issn=1532-0979|pmid=25188863}}</ref><ref>{{Cite journal|last=Kuo|first=Tseng-Tong|last2=Shih|first2=Lee-Yung|last3=Tsang|first3=Ngan-Ming|date=2004-10|title=Nasal NK/T cell lymphoma in Taiwan: a clinicopathologic study of 22 cases, with analysis of histologic subtypes, Epstein-Barr virus LMP-1 gene association, and treatment modalities|url=https://pubmed.ncbi.nlm.nih.gov/15494863|journal=International Journal of Surgical Pathology|volume=12|issue=4|pages=375–387|doi=10.1177/106689690401200410|issn=1066-8969|pmid=15494863}}</ref>.

{| class="wikitable sortable"

{| class="wikitable sortable"

EBER / EBV

EBER / EBV

|-

|-

|Positive (subset)||TCR αβ/γδ, pSTAT3, CXCL13, IRF4/MUM1, CD16, Fas, FasL, MATK, CD30

|Positive (subset)||TCR αβ/γδ, HLA-DR, CD25, pSTAT3, CXCL13, IRF4/MUM1, CD16, Fas, FasL, MATK, CD30

|-

|-

|Negative (universal)||CD4, CD8

|Negative (universal)||CD4, CD8