Non-Hodgkin lymphoma (NHL) refers to a very broad group of malignancies involving the lymphatic system. It excludes Hodgkin lymphoma, which is less common.

NHLs are subclassified based on the different types of lymphocytes involved. They can include B-lymphocytes, T-lymphocytes, and natural killer cells. B-cell lymphomas are the most common and include diffuse B-cell lymphoma, cutaneous B-cell lymphoma, follicular lymphoma, chronic lymphocytic leukemia, acute lymphocytic leukemia, mantle cell lymphoma, marginal zone lymphomas, Burkitt lymphoma, lymphoplasmacytic lymphoma, and central nervous system lymphoma. T-cell lymphomas include peripheral T-cell lymphoma, anaplastic large cell lymphoma, angioimmunoblastic T-cell lymphoma, and adult T-cell lymphoma / leukemia.

The signs and symptoms of NHL are very heterogeneous, depending on the subtype of malignancy. It can involve lymph nodes, skin, the gastrointestinal system, the liver, the spleen, bone marrow, or any other part of the body.

It is critical to diagnose the type of NHL in order to correctly treat it.