InterLymph hierarchical classification of lymphoid neoplasms for epidemiologic research based on the WHO classification (2008): update and future directions.
After publication of the updated World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues in 2008, the Pathology Working Group of the International Lymphoma Epidemiology Consortium (InterLymph) now presents an update of the hierarchical classification of lymphoid neoplasms for epidemiologic research based on the 2001 WHO classification, which we published in 2007. The updated hierarchical classification incorporates all of the major and provisional entities in the 2008 WHO classification, including newly defined entities based on age, site, certain infections, and molecular characteristics, as well as borderline categories, early and "in situ" lesions, disorders with limited capacity for clinical progression, lesions without current International Classification of Diseases for Oncology, 3rd Edition codes, and immunodeficiency-associated lymphoproliferative disorders. WHO subtypes are defined in hierarchical groupings, with newly defined groups for small B-cell lymphomas with plasmacytic differentiation and for primary cutaneous T-cell lymphomas. We suggest approaches for applying the hierarchical classification in various epidemiologic settings, including strategies for dealing with multiple coexisting lymphoma subtypes in one patient, and cases with incomplete pathologic information. The pathology materials useful for state-of-the-art epidemiology studies are also discussed. We encourage epidemiologists to adopt the updated InterLymph hierarchical classification, which incorporates the most recent WHO entities while demonstrating their relationship to older classifications.
Turner
Jennifer J
JJ
Department of Histopathology, Douglass Hanly Moir Pathology, and the Australian School of Advanced Medicine, Macquarie University, Sydney, Australia. jtur8838@bigpond.net.au
Morton
Lindsay M
LM
Linet
Martha S
MS
Clarke
Christina A
CA
Kadin
Marshall E
ME
Vajdic
Claire M
CM
Monnereau
Alain
A
Maynadié
Marc
M
Chiu
Brian C-H
BC
Marcos-Gragera
Rafael
R
Costantini
Adele Seniori
AS
Cerhan
James R
JR
Weisenburger
Dennis D
DD
D016021:Epidemiologic Studies; D006801:Humans; D008223:Lymphoma / Q000145:classification* / Q000453:epidemiology* / Q000473:pathology; D012955:Societies, Medical; D014944:World Health Organization