Light micrograph section through a human spleen showing Hodgkin's lymphoma. This disease can arise in many organs in the body such as in the liver, bone, lung and in this case the spleen. The spleen is a large organ to the left of the stomach. It is part of the lymphatic system and it helps to filter old or damaged blood cells and fights infection. Furthermore, Hodgkin's lymphoma can occur in either the tonsils or a gland in the chest called the thymus, but this is very rare. If Hodgkin's lymphoma is found in parts of the body outside the lymphatic system, it is called extranodal disease.