A lymphoma is a type of cancer that affects the lymph system, which is part of the body's immune system. The two main types of lymphoma are Hodgkin lymphoma and non-Hodgkin lymphoma.

Lymphomas are more common in men than in women. In most cases the cause is not known. Symptoms of lymphoma include swelling in one or more groups of lymph nodes, weakness, fever, weight loss, and an enlarged liver and spleen.

Depending on the type of lymphoma and whether it is confined to a single group of lymph nodes or affects many lymph nodes, treatment may include radiation therapy, chemotherapy, targeted therapy, or a stem cell transplant.