The 2008 WHO classification of lymphomas: implications for clinical practice and translational research

Abstract

The 4 th edition of the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues published in 2008 builds upon the success of the 2001 3 rd edition; new entities are defined, and solutions for problematic categories are sought. Recent studies have drawn attention to the biological overlap between classical Hodgkin lymphoma (CHL) and diffuse large B-cell lymphomas (DLBCL). Similarly, there is a greater appreciation of the borderlands between Burkitt lymphoma and DLBCL. Strategies for the management of these borderline lesions are proposed. Additionally, age-specific and site-specific factors play an important role in the definition of several new entities, which also have biological underpinnings. Among the peripheral T-cell lymphomas (PTCL), more precise definitions were introduced for several entities, including anaplastic large cell lymphoma, angioimmunoblastic T-cell lymphoma, enteropathyassociated T-cell lymphoma, and subcutaneous panniculitis-like T-cell lymphoma. Several new variants of primary cutaneous T-cell lymphomas are proposed. Finally, the subclassification and categorization of the most common lymphoma subtypes, follicular lymphoma (FL) and DLBCL, were altered to enhance diagnostic accuracy and aid in clinical management. The 2008 WHO classification also draws attention to early events in lymphomagenesis. These lesions help delineate the earliest steps in neoplastic transformation and generally mandate a conservative therapeutic approach. The 2001 classification was rapidly adopted for clinical trials and successfully served as a common language for scientists comparing genetic and functional data. The modifications made in the 2008 classification are the result of this successful partnership among pathologists, clinicians, and biologists, but are only a stepping stone to the future.

Activity and safety of dose‐adjusted infusional cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy with rituximab in very elderly patients with poor‐prognostic untreated diffuse large B‐cell non‐Hodgkin lymphoma

“…Patients eligible for the study had previously untreated DLBCL, according to the World Health Organization classification of lymphoid neoplasms, 20 were aged 70 years and over, and had at least 2 adverse prognostic factors as defined by the age-adjusted International Prognostic Index (IPI) for non-Hodgkin lymphoma. 2 Patients were also required to have adequate organ function as defined by a left ventricular ejection fraction (LVEF) !50%, serum creatinine <150 lmol/L, serum bilirubin <30 lmol/L, control of other medical conditions such as infection or cardiac disease, white blood cell count !3.5 Â 10 9 /L and platelet count !100 Â 10 9 /L unless caused by lymphoma infiltration of marrow or spleen.…”

Prediagnostic circulating concentrations of plasma insulin‐like growth factor‐I and risk of lymphoma in the European Prospective Investigation into Cancer and Nutrition

“…While lymphomas have traditionally been classified as either Hodgkin lymphoma (HL) or non‐Hodgkin lymphoma (NHL), in this analysis lymphomas were categorised, as in previous EPIC lymphoma papers,13 according to the current World Health Organization (WHO) classification of haematopoietic and lymphoid tumours,14 which differentiates between B‐cell neoplasms, T‐cell tumours, HL, and based on distinct morphologic, immunophenotypic, and genetic features. Cases comprised 897 B‐cell lymphoma (BCL), 34 T‐cell, 51 HL, and 90 other subtypes of lymphoma.…”

Pyrexia, Lung nodules, Granulomas: Pulmonary Lymphomatoid Granulomatosis

“…For the next 20 years this clinical entity remained in controversy for its exact etiology. Immunophenotyping and molecular techniques like PCR and EBV encoded RNA in situ hybridization techniques (EBER ISH) have confirmed it to be an EBV associated mature B-cell neoplasm [2]. Viral proteins normally induce cytotoxic T cell response, which appears to be deficient in LYG.…”