Classification of non Hodgkin's lymphoma (NHL)

Classification

Several different classification systems have been brought forward over the past few years but none have gained universal acceptance.

• historically NHL was classified according to the International Working Formulation (IWF) as either low, intermediate or high grade based on the morphology and natural history (1).
• currently the Revised European American Lymphoma (REAL)/WHO classification is in use

REAL/WHO classification

B-cell neoplasms

1. Precursor B-cell neoplasm: precursor B-acute lymphoblastic leukaemia/lymphoblastic lymphoma (LBL).
2. Peripheral B-cell neoplasms

• B-cell chronic lymphocytic leukaemia/small lymphocytic lymphoma.
• B-cell prolymphocytic leukaemia.
• Lymphoplasmacytic lymphoma/immunocytoma.
• Mantle cell lymphoma.
• Follicular lymphoma.
• Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphatic tissue (MALT) type.
• Nodal marginal zone B-cell lymphoma (± monocytoid B-cells).
• Splenic marginal zone lymphoma (± villous lymphocytes).
• Hairy cell leukaemia.
• Plasmacytoma/plasma cell myeloma.
• Diffuse large B-cell lymphoma.
• Burkitt lymphoma.

T-cell and putative NK-cell neoplasms

1. Precursor T-cell neoplasm: precursor T-acute lymphoblastic leukaemia/LBL.
2. Peripheral T-cell and NK-cell neoplasms.

• T-cell chronic lymphocytic leukaemia/prolymphocytic leukaemia.
• T-cell granular lymphocytic leukaemia.
• Mycosis fungoides/Sézary syndrome.
• Peripheral T-cell lymphoma, not otherwise characterized.
• Hepatosplenic gamma/delta T-cell lymphoma.
• Subcutaneous panniculitis-like T-cell lymphoma.
• Angioimmunoblastic T-cell lymphoma.
• Extranodal T-/NK-cell lymphoma, nasal type.
• Enteropathy-type intestinal T-cell lymphoma.
• Adult T-cell lymphoma/leukaemia (human T-lymphotrophic virus [HTLV] 1+).
• Anaplastic large cell lymphoma, primary systemic type.
• Anaplastic large cell lymphoma, primary cutaneous type.
• Aggressive NK-cell leukaemia.

Reference

1. Alaggio R, Amador C, Anagnostopoulos I, et al. The 5th edition of the World Health Organization classification of haematolymphoid tumours: lymphoid neoplasms. Leukemia. 2022 Jul;36(7):1720-48.