Understanding of lymphoid neoplasms has evolved over the past 50 years, resulting in numerous classification schemes for these cancers, and particularly for non-Hodgkin lymphomas. In 2007, the International Lymphoma Epidemiology Consortium (InterLymph) Pathology Working Group published a proposed nested classification of lymphoid neoplasms1 based on the World Health Organization classification of lymphoid neoplasms and the International Classification of Diseases-Oncology, Third Edition (ICD-O-3). This classification scheme was designed to facilitate epidemiologic studies of lymphoma subtypes.

The SEER publishes incidence rates, incidence trends and survival based on the SEER lymphoid malignancy recode variable (Hodgkin Lymphoma and Non-Hodgkin Lymphoma, respectively). The SEER lymphoid malignancy recode variable was also added to the SEER databases as a convenience for researchers.

Variable Definitions

Version Definition
Lymphoid neoplasm recode 2021 Revision
  • Based on ICD-O-3, updated for Hematopoietic codes based on WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (2008).
  • This variable does not incorporate Grade. Earlier versions used for diagnoses prior to 2017 did use Grade.
  • Recommended variable for use in the 1975-2018 SEER Research Data (November 2020 submission).
Lymphoid neoplasm recode 2020 Revision
  • Based on ICD-O-3, updated for Hematopoietic codes based on WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (2008).
  • This variable does not incorporate Grade. Earlier versions used for diagnoses prior to 2017 did use Grade.
Lymphoma Subtype Recode/WHO 2008
  • Based on ICD-O-3, updated for Hematopoietic codes based on WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (2008).
  • Recommended variable for use in the 1973-2010 SEER Research Data (November 2012 submission) and later releases.
  • Starting with the November 2020 submission, this variable's name includes "(thru 2017)" and the field is not coded for 2018 or later diagnoses.
Lymphoma Subtype Recode (Original Definition)
  • Based on ICD-O-3
  • Recommended variable use in the 1973-2009 SEER Research Data (November 2011 submission) and earlier versions.
  • Starting with the November 2020 submission, this variable's name includes "(thru 2017)" and the field is not coded for 2018 or later diagnoses.

1Adapted from Morton LM, Turner JJ, Cerhan JR, Linet MS, Treseler PA, Clarke CA, Jack A, Cozen W, Maynadié M, Spinelli JJ, Costantini AS, Rüdiger T, Scarpa A, Zheng T, Weisenburger DD. Proposed classification of lymphoid neoplasms for epidemiologic research from the Pathology Working Group of the International Lymphoma Epidemiology Consortium (InterLymph). Blood 2007;110:695-708.