Non-Hodgkin Lymphomas By Peter Martin, MD, Weill Cornell Medicine; John P Leonard, MD, Weill Cornell Medicine Reviewed / Revised May 2022 | Modified Sep 2022 View Patient Education Etiology Pathophysiology Classification Symptoms and Signs Diagnosis Prognosis Treatment Key Points More Information Topic Resources Non-Hodgkin Lymphoma (Cervical... Non-Hodgkin Lymphoma (Posterior... Lugano Staging of Hodgkin... Non-Hodgkin lymphomas are a heterogeneous group of disorders involving malignant monoclonal proliferation of lymphoid cells in lymphoreticular sites, including lymph nodes, bone marrow, the spleen, the liver, and the gastrointestinal tract.