All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Classification of non-Hodgkin's lymphomas
Medical expert of the article
Last reviewed: 04.07.2025
Non-Hodgkin's lymphomas are tumors of lymphoid cells of various histogenetic origins and degrees of differentiation. The group includes more than 25 diseases. Differences in the biology of non-Hodgkin's lymphomas are due to the characteristics of the cells that form them. It is the constituent cells that determine the clinical picture, sensitivity to therapy, and long-term prognosis. Specific non-random chromosomal translocations and receptor rearrangements are known for most lymphomas, which are of key importance in pathogenesis.
According to the Classification of Tumor Diseases of Hematopoietic and Lymphoid Tissue adopted by WHO in 1999, types of non-Hodgkin's lymphomas are determined based on morphology, immunophenotype, genetic characteristics of tumor cells and clinical presentation of the disease.
The classification is based on the proposals of the Lymphoma Study Group, which combined the main positions of the Kiel (primarily European) classification and the so-called Working Formulation used in the USA and Canada.
Non-Hodgkin's lymphomas are divided into main groups depending on their belonging to T- or B-line lymphopoiesis. Further detailing is determined by the degree of differentiation of tumor cells, localization and histological structure of the tumor, and features of the course of the disease.
[ Main types of non-Hodgkin's lymphomas in children
In children, the spectrum of histological variants of non-Hodgkin's lymphomas is relatively narrow. It has been proven that all types are generalized already at the earliest stages of presentation, and in 95% of cases - highly malignant. Tumors develop mainly from precursor cells of T- and B-lymphocytes, have a diffuse histological structure. Based on morphological and histological characteristics, childhood non-Hodgkin's lymphomas can be divided into three main groups - Burkitt's lymphomas (and Burkitt-like), lymphoblastic and large cell. This classification practically corresponds to the sections of the Working Formulation and is convenient from the point of view of therapy (the protocols for the treatment of childhood non-Hodgkin's lymphomas used in Russia, developed by the BFM group, suggest a similar division into three main therapeutic groups). However, this approach caused an error in determining the treatment tactics for children with large-cell lymphomas in the first years of using the above-mentioned protocols in Russia, when patients were treated according to the protocol for anaplastic large-cell lymphoma, while variants of diffuse large-cell lymphomas from B-lymphocyte precursors require more aggressive therapy. Currently, diagnostics of non-Hodgkin's lymphomas should be carried out in accordance with the international WHO protocol.
The following histological variants of non-Hodgkin's lymphomas are typical for children under 15 years of age.
- Lymphoblastic lymphomas, in the overwhelming majority of cases consisting of T-, rarely (about 10%) of B-precursor cells;
- Diffuse B-cell, 70% of which is Burkitt's lymphoma and Burkitt-like with mature cell B-immunophenotype. The obligatory elements of which are the presence of surface IgM (or light chains), high proliferative index Ki 67 (up to 100% of cells), the presence of C-mic rearrangement, specific translocations 8; 14, 8; 22 and 2; 8.
- Large cell lymphomas (15-20% of childhood lymphomas) belonging predominantly to the B-lineage of lymphopoiesis.
Among large cell lymphomas, several variants are distinguished, which does not affect the choice of treatment tactics. One third of childhood large cell lymphomas are anaplastic large cell lymphoma with T-immunophenotype (very rarely B-cell or from cells that do not carry either T- or B-cell markers), activation marker CD30 and specific chromosomal translocation between regions of chromosomes 2 and 5 - t (2;5) - with the participation of the anaplastic lymphoma kinase gene (alk).
Rarely, in no more than 5% of patients, other types of non-Hodgkin's lymphomas are diagnosed - peripheral large cell, follicular, true histiocytic, unclassifiable.
Very high proliferative potential causes rapid growth of childhood lymphomas.