Natural Killer/T-Cell Lymphoma in Children and Adolescents: Clinicopathologic and Gene Expression Profiling Study of 22 Cases

Abstract Background: There have been few studies on large-scale samples regarding natural killer/T-cell lymphoma (NKTCL) in children and adolescents for the low incidence of NKTCL in this age group. The clinical, histopathological and molecular features of 22 young people with NKTCL were evaluated. The aim of the present study was to provide a better understanding of the clinicopathological aspects of this rare entity of lymphoma.Results: There were 15 male and 7 female patients (male/female, 2.14:1) with a median age of 15 years. The results revealed that the nasal site was the most involved region while non-nasal sites were observed in 27.3% out of all cases, and exhibited histopathological and immunohistochemical features similar to the cases in adults. Seven (36.8%) out of all the 19 patients during the follow-up died of the disease, and the median follow‑up period was 44 months. Moreover, patients treated with radiotherapy/chemotherapy showed significantly inferior OS compared with the untreated patients. High mutation frequencies were detected including KMT2C (5/5), MST1 (5/5), HLA-A (3/5) and BCL11A (3/5), which involved in modifications, tumor suppression and immune surveillance. Conclusion: NKTCL in children and adolescents is a rare type of T/NK cell neoplasms. This disease is difficult to distinguish from other EBV-related disorders in young people. Furthermore, active treatment is necessary after the diagnosis of NKTCL is confirmed.