Lymphadenectomy Specimens in a Large Retrospective Cohort of Pediatric Patients Reveal No in situ Lymphomas but a Broad Spectrum of Reactive Changes.
OBJECTIVE
While the incidence and prevalence of in situ follicular neoplasia (ISFN) and in situ mantle cell neoplasia (ISMCN) in adults are well documented, little is known about these early (precursor) lesions in pediatric populations. The aim of this study was to analyze so-called 'reactive' lymph nodes harvested for the purpose of staging solid tumors, unexplained lymphadenopathies, or presumed inflammatory processes or in conjunction with other surgical interventions in children and adolescents aged <18 years, with special attention to ISFN and ISMCN.


METHODS
Formalin-fixed, paraffin-embedded reactive lymph node samples from an unselected pediatric population from two catchment areas in Switzerland were retrospectively analyzed for the presence of ISFN and ISMCN and specific reactive lymph node patterns.


RESULTS
While a diverse range of histopathological patterns of reactive lymph node changes with a particular periodic increase in mycobacterioses could be observed in this pediatric population, not a single case of ISFN or ISMCN was found.


CONCLUSIONS
Early histological lymphomagenesis equivalents in the form of in situ lymphomas are exceedingly rare events in children and young adolescents. The spectrum of reactive lymph node changes is large, with differences possibly determined by regional variations in geography, demographics, catchment areas, seasons, and years, respectively.
Institute of Pathology, University of Bern, Bern, Switzerland.
Yara
Y
Banz
Alexandar
A
Tzankov
Stephan
S
Dirnhofer
Aurel
A
Perren
Sylvia
S
Hoeller
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003710:Demography; D005260:Female; D006801:Humans; D007223:Infant; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery; D008223:Lymphoma / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D008224:Lymphoma, Follicular / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D020522:Lymphoma, Mantle-Cell / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D008297:Male; D012189:Retrospective Studies; D013557:Switzerland
Follicular lymphoma; Immunodeficiency; Mantle cell lymphoma