Lymphoma is a type of cancer that affects the lymphatic system of the body, which is part of the body's germ-fighting network.
The lymphatic system includes the lymph nodes (lymph glands), spleen, thymus gland, and bone marrow.
Lymphoma can affect all those areas as well as other organs throughout the body.
It begins when a disease-fighting white blood cell called a lymphocyte develops a genetic mutation that leads the cell to multiply rapidly, causing many diseased lymphocytes that continue multiplying.
Symptoms of lymphoma include:
Painless swelling in lymph nodes around neck, armpits, and groin.