title: Adenotonsillar histopathology after organ transplantation.
abstract: OBJECTIVE
  The increasing number of surviving pediatric organ transplant recipients has resulted in a new clinical controversy surrounding the significance of adenotonsillar hypertrophy. The objective of this study is to evaluate adenotonsillar specimens, understand characteristic histopathology, and to examine the frequency and significance of this finding in this population.
  
  
  METHODS
  Twenty-one cases of pediatric transplant recipients with adenoidal and/or tonsillar hypertrophy were reviewed retrospectively in a tertiary-care setting. Particular attention was given to the histopathology of their surgical specimens, including any evidence of posttransplantation lymphoproliferative disorders (PTLD).
  
  
  RESULTS
  Using morphologic, immunohistochemical, and molecular genetic analyses, 15 (71%) of 21 patients were noted to have Epstein-Barr virus (EBV)-related lymphoid hyperplasia, including 1 case (4.7%) of PTLD. Six (29%) of 21 had evidence of reactive follicular hyperplasia not related to EBV. B-cell and T-cell markers were nearly uniformly positive when tested for, except in the single patient with PTLD, who exhibited polymorphic, polyclonal B-cell morphology. Kappa and lambda light-chain clonality markers were positive in 11 (92%) of 12 patients.
  
  
  CONCLUSIONS
  EBV-related lymphoid hyperplasia is frequently associated with adenotonsillar hypertrophy in pediatric organ transplant patients (71% of our cases); 92% of those cases tested exhibit polyclonal B-cell populations. PTLD, an important cause of morbidity and mortality in this population, represented approximately 5% of our cases. The remainder of cases represent follicular hyperplasia unrelated to EBV or lymphoproliferative abnormalities. Characteristic histopathologic findings are presented.
authors.affiliation: Division of Head and Neck Surgery, Department of Surgery, UCLA School of Medicine, Los Angeles, California 90095-1624, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Williamson
authors.forename: R Y
authors.initials: RY
authors.lastname: Huang
authors.forename: N L
authors.initials: NL
authors.lastname: Shapiro
mesh_terms: D000234:Adenoids / Q000382:microbiology / Q000473:pathology*; D000293:Adolescent; D002648:Child; D005260:Female; D004854:Herpesvirus 4, Human / Q000302:isolation & purification; D006801:Humans; D006965:Hyperplasia; D006984:Hypertrophy; D007150:Immunohistochemistry; D007223:Infant; D008232:Lymphoproliferative Disorders / Q000209:etiology* / Q000473:pathology*; D008297:Male; D016377:Organ Transplantation / Q000009:adverse effects*; D014066:Palatine Tonsil / Q000382:microbiology / Q000473:pathology*; D012189:Retrospective Studies