Clusters of lymph nodes are found in the underarm, pelvis, neck, and abdomen. The lymph nodes make and store infection-fighting cells. Because lymph tissue is found in many parts of the body, non-Hodgkin's lymphoma can start in almost any part of the body. The cancer cells in Hodgkin's disease look a certain way under a microscope. There are many types of non-Hodgkin's lymphomas.
Some types spread more quickly than others.
The type is determined by how the cancer cells look under a microscope. This determination is called the histology. If these symptoms are present, a doctor will carefully check for swelling or lumps in the neck, underarms, and groin. If the lymph nodes don't feel normal, a doctor may need to surgically remove a small piece of tissue and look at it under a microscope to see if there are any cancer cells. This procedure is called a biopsy.