Non-Hodgkin lymphoma is a form of cancer that starts in the lymphocytes, which are cells of the lymphatic system. Lymphocytes exist in the lymph nodes and other lymphoid tissues and are part of the body’s immune system, according to the American Cancer Society.
The cause of non-Hodgkin lymphoma is not fully understood. Under normal conditions, lymphocytes die as part of their regular life cycle, only to be replaced by new ones. In non-Hodgkin's lymphoma, old cells do not die. They continue dividing and growing, creating an oversupply of lymphocytes, according to Mayo Clinic.
While symptoms depend on what part of the body is affected and by how far the cancer has progressed, they usually include swollen lymph nodes in the neck, armpits or groin, abdominal pain or swelling, fever and chills, coughing or trouble breathing, fatigue, and weight loss. Diagnosing the disease generally begins with a physical examination, but it may also include blood tests, gallium scans, CT scans, PET scans, MRI imaging or a lymph node biopsy, as described by Medline Plus. Treatment depends on the type of lymphoma and the stage of the disease as well as the age of the patient and their overall health. Options include chemotherapy, radiation therapy, stem cell transplant and medications that help the body's immune system fight cancer, notes Mayo Clinic.