Primary Nonanaplastic Peripheral Natural Killer/T-Cell Lymphoma in Pediatric Patients—An Unusual Distribution Pattern of Subtypes

Abstract

Peripheral NK/T-cell lymphoma (PNKTCL) represents a group of uncommon diagnoses for children in Western countries, and studies have often necessitated multiple institutions to assemble enough cases. We retrospectively analyzed 11 cases of nonanaplastic PNKTCL in children over 19 years at our institution with comparison to several published large multiinstitutional studies. Patients included 9 males and 2 females of white (5), Native American (3), and Hispanic (3) background with 6 cases of extranodal NK/T-cell lymphoma, nasal type (EN-NKTL, 54.6%), 3 cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS, 27.2%), and 2 cases of systemic Epstein-Barr virus (EBV)-positive T-cell lymphoma of childhood (18.2%). Compared to the literature, our institution exceeded in frequency of total nonanaplastic PNKTCL (4.8% vs 0.9%-1.6%) with lesser relative incidence of PTCL-NOS (27.2% vs 42.9%-66.7%) and greater relative incidence of EN-NKTL (54.6% of cases vs 12.5%-47.6%), which significantly exceeded the literature's rate for Western institutions (13.5%). Potential influencing factors include population structure approximating those of non-Western countries with high EN-NKTL prevalence and the predisposition for EBV infection in this demography. These data suggest an uneven distribution of nonanaplastic PNKTCL in Western countries, and differential diagnoses may differ depending on practice location and associated patient population.

A retrospective study on the clinicopathological and molecular features of 22 cases of natural killer/T-cell lymphoma in children and adolescents

“…In China, NKTCL is the second most common type of lymphoma following diffuse large B-cell lymphoma (DLBCL) 3 . Although NKTCL can occur in children and adolescents, studies with large samples are not available due to the low incidence of NKTCL in this age group 4 – 7 . Recently, Hang reported 17 NKTCL cases from 2012 to 2014 in which the patients were younger than 17 years of age and having an occupancy of 6% (17/286) of the total sample size during the same period 8 .…”

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

“…In China, NKTCL is the second most common type of lymphoma following diffuse large B-cell lymphoma (DLBCL) [3] . Although NKTCL can occur in children and adolescents, studies with large samples are not available due to the low incidence of NKTCL in this age group [4][5][6][7] . In this study, we reviewed the clinicopathologic and genetic features of young patients with NKTCL at our institution in China.…”