Lymph vessels and nodes of pelvis
Lymph nodes function as part of the immune system to protect against and fight infection, inflammation, and cancers. Lymph nodes are small structures that filter the lymph fluid that consists of liquids, fats, proteins, and other substances within the body. If cancer exists in the prostate, the first means it has of spreading is through the pelvic lymph nodes. Whether cancer is present in any or all of the nodes is an important factor in determining the appropriate treatment for each patient.