title: Extranodal Natural Killer/T-Cell Lymphoma in Children and Adolescents: A Report of 17 Cases in China.
abstract: OBJECTIVE
  To investigate the clinicopathologic features of extranodal natural killer/T-cell lymphoma (ENKTL) not preceded by another Epstein-Barr virus (EBV)-related disorder in children and adolescents.
  
  
  METHODS
  A series of 17 cases of ENKTL not preceded by another EBV-related disorder in children and adolescents in one institution from China was retrospectively analyzed.
  
  
  RESULTS
  The patients had a median age of 13 years (range, 2-17 years), and the male to female ratio was 3.25:1. All the patients were of Chinese origin and without a history of another EBV-related disorder. The upper aerodigestive tract was involved in 14 (82.4%) cases, of which the sinonasal region was involved in 10 (58.8%) cases. Twelve (70.6%) patients had stage I/II disease. Morphologically, coagulative necrosis and angiocentric/angiodestructive growth pattern were observed in 94.1% (16/17) and 88.2% (15/17) of all cases, respectively. Thirteen (76.5%) cases were mainly composed of medium-sized cells. All cases expressed cytoplasmic CD3 and at least one marker for cytotoxic granules. CD56 expression was seen in 16 (94.1%) of 17 cases. Each case harbored EBV.
  
  
  CONCLUSIONS
  ENKTL not preceded by another EBV-related disorder in children and adolescents is occasionally observed in China. It tends to have a male predominance. The upper aerodigestive tract, especially the sinonasal region, is the most commonly involved site. The morphologic features and immunophenotype in children and adolescents are similar to that occurring in adults.
authors.affiliation: From the Department of Pathology, Beijing Friendship Hospital, Capital Medical University Beijing, China; Department of Pathology, Shenzhen Second People's Hospital, Shenzhen, China;
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Huang
authors.affiliation: From the Department of Pathology, Beijing Friendship Hospital, Capital Medical University Beijing, China;
authors.forename: Jianlan
authors.initials: J
authors.lastname: Xie
authors.affiliation: From the Department of Pathology, Beijing Friendship Hospital, Capital Medical University Beijing, China; Department of Pathology, the First Affiliated Hospital of Xiamen University, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Ding
authors.affiliation: From the Department of Pathology, Beijing Friendship Hospital, Capital Medical University Beijing, China; zhouxiaoge59@hotmail.com.
authors.forename: Xiaoge
authors.initials: X
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000473:pathology*; D016411:Lymphoma, T-Cell, Peripheral / Q000473:pathology* / Q000628:therapy; D008297:Male; D016896:Treatment Outcome
keywords: Children and adolescence; China; Clinicopathologic features; Epstein-Barr virus; Extranodal NK/T-cell lymphoma; Immunophenotype; Occurrence